Key Post: Central Heating

Rutigur,

There is some discussion/argument between Glenamaddy (Heating and Plumbing Contractor) and others in this link Cost of central heating which may help you with your enquiries.
 
central heating/question about condensing boilers

Hi Rutigur!
Your first question about the power shower:Call the county council and ask them about the water pressure in your area.There might be a pressure gauge somewhere at your water system,usually at the meter and/or at the boiler.
Having found out the pressure you can decide what you can have.Power showers are usually not necessary once you have a pressure above 1.5 bar.But have a look at the main water pipe coming in to your house:If it has a diameter of 21mm or more (and the pressure is correct) it is absolutely no problem to use a combi condensing boiler for the shower as well,you would have plenty of pressure (I assume your house to be of the standard type,2 storeys).Even if the diameter is smaller than 21mm it might still be good enough .There are also combi condensing boilers for open fresh water systems available.You can buy a pressure gauge from B&Q for € 5 or €10.
Combi condensing boilers are mandatory in the Netherlands for example-as long as the builder does not decide to go for example for a solar system which would get an approval from the building controllers/planners even if "backed-up" by electricity.
Dublin City Council have no say in what you do in your house.That would be a joke if they try to ban direct feed water heaters-honestly,I have never heard about such an attempt.But you better ask,since they loose 40% of their water through leaks they might not be the fittest in terms of conservation/logic thinking/responsible workmanship.
The concern that they might have:to much demand on the water system.But check the site of www.irish-energy.ie/ They tell us there that builders get subsidies to put in combi condensing boilers,it would be very odd that they subsidise builders for conservation but would forbid the same for the private home owner....but we are in Ireland,better ask.
The job of plumbing a combi condensing boiler is considerably less work than the traditional British system.
And you are right:you save the hot press,the power shower,the tanks in the attic,the chimney and the chimney sweeper,the oil tank and/or coal shed.Saving the chimney alone would buy any home builder 2 condensing boilers instead......
I have a combi condensing boiler myself (€1400.- VAT)and I am more than happy with it.
 
Re: >>Central Heating

Hi everyone

I want to install dual central heating in the house I'm buying and am looking for advice. I've had very little dealings with any tradesmen in the past but the little contact I've had with (even recommended) plumbers has not been very reassuring.
I will need an oil boiler, tank, stove (solid fuel) and about 9 or 10 radiators.
Going by what was said before here, I'm allowing a rough estimate of €10,000 for this. Does this sound reasonable?
I also want to get a dishwasher plumbed in (right beside the current washing machine set-up) and have two WC pans & cisterns replaced (and possibly a sink). I was planning on buying the WCs, sink and stove myself although I'm afraid I might make a haymes of buying the stove.
I'm also worried about cosmetic aspects of the job. Will all the pipes run along the skirtings or will they go under the floorboards (where these are still in place)? Can I get the boiler put in the garage/shed approx 2-3m away from back door? Can I get the tank put at the back of this shed, which would mean it is quite a way from the road and house?
I'm trying to be as aware as I can before I start talking to them so they won't bamboozle me.
Thanks
Rebecca
 
Re: >>Central Heating

Your tank can go anywhere where there is reasonable access. You won't want them running the filler pipe through the house though. Not sure how long the normal "oil filler hose" is, perhaps you could ring the local provider and ask.

Why are you hooked on oil by the way? Have you considered a wood-pellet solid fuel system? I would consider this to be a better investment in the long run -- especially if you are planning on installing a solid-fuel stove anyway. There are a number of companies that can advise you in this area. I've had some dealings with http://www.glas.ie and [broken link removed] ,and there are others.

Just a thought.

As for the pipes - almost anything can be hidden. Plumbers complain about it but be firm. They'll spout a load of guff about making it harder to fix leaks etc etc but this is misleading, to say the least.
 
Re: >>Central Heating

For the €10.000 you get a top of the range condensing boiler plus all the other things like radiators,automatic valves , toilets and so on. Condensing boilers fit anywhere, under the counter, into the kitchen cup board etc..They are not much more noisy than a fridge/freezer unit.And they cost a fraction to run fuel wise compared to any other boiler.The worst place (energy loss ! ) for a boiler is outside or in an outhouse.

There was plenty of discussion here about the issue,check the earlier threads.
 
Re: >>Central Heating

Thanks extopia and heinbloed. I've read the ealier threads but I'm nervous because I don't see many houses around other than with oil tanks and I haven't the first clue about plumbing and heating myself (nor has anyone I know, other than how to bleed radiators etc). Any recommendation on a reliable plumber who could fit and maintain this kind of system in the west midlands? Someone who knows what they are doing, would turn up and not rip me off? I'd even pay more than the norm if I felt I could trust them.

Rebecca
 
Re: >>Central Heating

At http://www.sedbuk.com/ you can find oil burners and their efficiency.The manufacturers adresses/homepages are there as well.Contact them and ask where their nearest outlet/sales agent is based.Contact this shop and tell them in what situation you are,that you need this or that boiler and someone trained to install and commission the entire heating system. They usually have at least one plumber for you.He or she should be trained by the manufacturer of the boiler.Irish plumbers are usually incompetent to go for something that they haven't seen before.So it is important that you get the right person,someone who is trained by the manufacturer.He/she will be also the person for maintenance and guarantee cases.
I am saying this not because I don't like them.I read it again today at the home page of the Irish Energy Center.When you contact the manufacturer than ask for the price of the boiler,the recommended retail price.When you contact the shop than tell them freely that you have heard that there is a 20% off .Believe me,that is a normal proceeding,the r.r.p. is only for the plumbers to show on the bill to his client.No one pays this price who is in the trade.But sometimes the shop/retailer gives a good reduction by their own without asking."Heatmerchants" do so,at least in Cork.
Contact your County Council office and ask them for the water pressure in your street/adress. If you have more than 1.5 bar than you can opt for a pressurised system.That means you have plenty of water , hot or cold.And that means you can buy a combi condensing boiler.A combi condensing boiler will deliver hot water on demand,when you open the tap there will come hot water out of it.No need for a storage heater and a hot press , no need for the electrician to be involved.That safes money and increases your personal comfort as well as your living space.And the plumber has less to plumb-more savings- since there is less pipe work there is less chance for a leak.The tank in the attic can be dumped , no noisy splattering automatic refilling.And the place where the tank stood can now be insulated against heat loss through the ceiling.
So there are only benefits by using a a proper boiler.One that has more than 90% efficiency-see Sedbuk.
When you buy the radiator valves go not for the cheapest.The better ones are automatic ones-you set the temperature that you prefer in the room and they will maintain it.Closing the loop when the temperature has been reached and opening when it is falling below the set point.A dozen-or ten of them- come cheaper than the asking price for one multiplied with ten or twelve,ask for it in the shop where you buy the boiler.
Toilets and sinks can be put in by any plumber,you won't need the service of the trained condensing boiler plumber.But ask for the price , once at the job anyhow and he/she might give you a good deal.
The cheapest single lever mixing taps you get from IKEA or Argos. Plumbing shops are expensive for those things.I saw a few last week in B&Q and was shocked,at least three times what they cost on the continent,in IKEA (GB) and twice the price of Argos.Sinks are also much more expensive -about three times- in the plumber shop here than in IKEA (GB) or on the continent in general.
heinbloed
 
>>Conversion to gas central heating

Hi,

Bit of info/guidance needed. I am in the process of getting an extension planned (20sqm to rear, no PP required) and one of the things I'll be doing is converting from oil to gas. The old boiler house will be knocked down and the new boiler located inside the house (making a utility room out of a portion of the old kitchen). I wouldnt need a fancy combi boiler as one of the bathrooms has a power shower which uses a pump located in the hot press. There is side access (partly badly cobblelocked) and gas is available in the street and the house is approx 35 yrs old and located in north Dublin. I spoke briefly to the local gas installers who said a rough guide price (he had done some before in the estate) was €4,000. This included digging for the pipe to be laid, new boiler and flushing the system. He also said that some people who were changing over got their pipework replaced at the same time. He didnt however give any price for this. I'd like to ask if anyone has recently had the same done and if so what was the general price, 4k seems slightly on the high side, I have seen people give €2.5k-€4k as a ballpark price. Secondly is there generally a need to replace the old pipework if getting a new system in (we would be replacing a number of the rads downstairs)? I know noone can give a definitive yes or know without seeing the place, but any idea would be great. I dont want to get the conversion done and then find a year later that I should have done it at the time, but I also dont have an endless supply of money to throw at this, at this rate I could end up with an empty shell of an extension with microwave sitting on a chair. Thirdly, has anyone got an idea of the lad time to get the job done, I have heard it can take 2-3 months. Lastly (phew), any recommendations for good tradesmen/companies who do this kind of stuff. Any guidance will be greatly appreciated,

Thanks

Jack
 
Re: Conversion to gas central heating


If your pipework is all copper then it's fine and can be left as it is but if it's gunbarrel get it changed. Gunbarrel rots over time copper will not.
Bord Gais will recommend an approved installer.

[broken link removed]

Good Luck
 
Re: Conversion to gas central heating

Pay back time for a condensing boiler versus the wasters is 2 years . And you really don't need to conect the shower to it .
http://www.sedbuk.com compares the bangers with the technical advanced models . See yourself what they cost , you have a choice there of hundreds of models.
 
Re: Conversion to gas central heating

Thanks Heinbloed,

Interested in you saying that the boiler doesnt have to be connected to the shower. How would that work (as in how would the water for the power shower get heated if the boiler is producing hot water on demand and not filling the hot water tank, or have I got this arseways?)

Has anyone actually converted over recently and if so what were the general feelings/costs involved?

Jack
 
Re: Conversion to gas central heating

You can either use your boiler for home heating only or for delivering hot domestic water only or for home heating combined with domestic hot water . Neither the power shower nor the copper tank have to be ( but could be ) influenced by a condensing boiler. A combi condensing boiler would make the copper cylinder as well as the power shower obsolete . It depends on what you want.Go to the different manufacturers home pages via the Sedbuk page and have a look at their informations/technical details.
Savings of 15% between a banger and a condenser means that every 7. gas bill is for " free " so to say . A simple condensing boiler costs around € 1400.- , a combi model about € 500.- extra .And they last 10 jears or more.
 
Re: Conversion to gas central heating

Thanks lads,

I think I will ask the builder to quote for the work instead of having a separate contractor to worry about. If I ever manage to get my plans finalised and some quotes I will post the cost he proposes to charge me,

Jack
 
Re: Conversion to gas central heating

Good luck ! Again, go for the best boiler you can get. See [broken link removed]Gas prices going up by 20 % means a lot of money can be saved by an intelligent heating system and proper insulation .
 
Re: Conversion to gas central heating

Heinbloed, how difficult is it to change an existing outside boiler to a condesning boiler? I will be building a new room one of these days/months and I will probably need to move the outside boiler.

I have read with interest your enthusiasm for condenser boilers so I would see this as an opportunity to perhaps change the boiler. The control switch for the oil-heating system is currently in a utility room which I will more than likely be getting rid of to create an entrance to my new room. The condenser boiler would then have to go into a press somewhere. Are they relatively silent?

Is it a huge job to install a condensing boiler? Will there have to be digging of existing floors? Did I read correctly when you mentioned somewhere that one could also get rid of my current hot-water tank which is upstairs in a hot press?

I would like to know what I might be letting myself in for before I begin to track down a builder and ask him to do this particular job as part of the new building.

Marion
 
Re: Conversion to gas central heating

Hi Marion !

I’ll try my best to answer your question .

The first thing you have to keep in mind when installing a boiler is its position – where would it go. Once you have access to the “ flow and return “ pipes you can connect your boiler to those. Usually where there is a radiator in the room there is also an access to the pipes .

The next thing is to have a supply pipe feeding the boiler with fuel , which could be either oil or gas or LPG . If you have an oil tank in the garden then it is usually gravity feeding the boiler , the oil flows downwards to the burner .That means that your burner/boiler has to be positioned at a lower point as the tank to receive the fuel . That is the standard situation . But there are also oil pumps available that would pump the oil upwards to the boiler .

If you have a gas or LPG supply it is easier . Since gas and LPG come pressurized they go where the pipe leads them – up or down to the boiler .

The third point to look out for is the flue outlet . With the old energy wasting boilers a chimney was necessary . Because of the high temperatures of the flue gas (“smoke”) it would be dangerous not to lead them away from humans or any other heat sensitive material .And the gases ( carbon dioxide and sooth ) are dangerous/noxious as well . Therefore the chimney .

The condensing boiler masters these two “ problems “ by its technical design . The flue gases are cold , not hotter than about the flow temperature of your heating system. . That means if you run your radiators on 80 degrees – which would be quiet hot – than the flue gasses would have about the same temperature , maybe 5 degrees more or less .If you run the flow temperature at a lower temperature – for example floor or wall heating – at lets say 40 degrees than the flue gas temperature will be at around 35 degrees .

So a chimney for the reason of fire safety is – with a condensing boiler- not necessary at all. You need no chimney. But the boiler would still release carbon dioxide . Which can kill if the concentration is high enough in the air you breath . Therefore the condensing boiler has a flue pipe leading the flue gases outside . Since the temperature of flue gases are so low this flue pipe can be made of cheap plastic . For safety reasons ( the carbon dioxide ! ) it is important to build this pipe so it will end at least 40 cm away from a fresh air supply of the house . These air supplies are a.) windows that can be opened b.) all doors and c.) any air vent , mechanically vented or naturally venting .

So. These are the safety features you or your installer have to adhere to . The outlet pipe has to be 40 cm away from any air inlet.

The flue pipe consists of two pipes , one in the other . The inner one leading the fumes out and the outer one letting the fresh air in ( oxygen ! ) to the flame/burner.This solves the sound problem : Since the condensing boiler is a “ sealed system “ it needs no air supply from the room where it is installed . That means it runs quiet . Compare a radio sound from the next room with the door open and with the door closed to understand the point . Sound insulation is mainly achieved by sealing the source .

So since the condensing boiler needs no air supply from the room where it is installed can be placed anywhere . Even in the bedroom – but that would need further sound insulation by for example building a coup board around it . I have mine placed in the kitchen , it is not louder than a fridge of the 80’s but slightly louder than a modern fridge . I have it not further insulated ( no cupboard around it ) even so the kitchen is an open plan type . It can be heard firing up when it runs on full power for the first few seconds . But then it modulates down to the required demand of power.

Here we come to the two differences in condensing boilers : The modulating ones and the non modulating ones .

The difference is this : The non modulating condensing boiler fires up until the desired temperature of the “ flow “ is reached and then it switches the burner off until the temperature drops far enough to trigger the burner to switch on again . And so on . You know it from your old boiler .

The “ modulating ” condensing boiler fires up as well but then it senses the demand of the flow and reduces the flame down – but still firing - to keep it running as long as possible with out overheating the “ flow ” . It aims to keep the flow at a steady temperature as long as possible with the flame on . It does so for two reasons . First it saves energy : because when a burner fires up at a higher temperature the flue gases are higher as well – that means more loss through the outlet. Secondly it reduces the number of ignitions giving a better usage rate of the system ( running hours ), the longer it is in use the more economic is a

system . Compare it with a taxi : as long as it is transporting/running it is economical , no matter how slow it drives . But if it is standing idle the half day it is not economical , no matter how fast it drives the other half of the day.

So a modulating boiler is cheaper to run and more quiet , more quiet because when running in the modulated modus it burns less gas/oil/LPG . Compare it with the noise a car makes when speeding or when waiting at the red light . The engine is running but it is not as loud.

Can the hot press/the copper cylinder be dumped ? Yes , if you buy a so called “combi” boiler . Combi boilers are available as modulating condensing boilers , as non modulating condensing boilers and as ordinary boilers . The major point is , as you have said , that this boiler delivers hot domestic water . As well as heat for the home heating.

This demands a water supply to feed it and an outlet pipe for taps , showers etc..

So placing a boiler somewhere central in the house makes sense. The water pipes won’t freeze and the supply ways are short . The shorter the pipes the cheaper it is to get hot water from the boiler to the tap . Because when you want lets say 43 degrees at the tap you have to set the boiler at 44 degrees –provided your hot water pipe is not to long and insulated . If it is longer the boiler has to be set at a higher temperature.

The both temperatures – hot domestic water and central heating flow – can be set individually , independently from each other . In a combi boiler .

But not in a “ not – combi- boiler “. In a “ not combi boiler “ – the type of boiler that you have now – the flow temperature for the radiators is heating not only the radiators but also the storage copper tank for the domestic hot water . That means double wasting of energy : firstly the temperature for the taps is to high , it has to be be mixed with cold water to prevent scalding . Secondly the storage tank has a capacity of at least a hundred liters . As long as this capacity is not at temperature it cools down the circulating water in the heating system . It has to switch on more often than necessary because it takes a long time to heat up a large quantity of water . And due to the size/large surface of it the tank cools down fast . “ Hot “ press means that heat is lost from the heating system . Imagine you wrap ice bags around the pipes of your heating system . Not very economical.

So the best place for a combi condensing boiler in an existing structure is – in my opinion – somewhere in/near the kitchen or somewhere in/near the bathroom . Near to a tap . The flue pipe can be extended up to ten meters long to the outside wall . When employing an additional fan than even longer .

So when you go for a combi boiler the most important thing – from the installers point – is to have enough fresh water . Phone your county council office and ask them about the pressure minimum in your area . With this number ( bars ) you then look for a combi boiler . The manufacturers give detailed information about the minimum/maximum pressure .

Check the Sedbuk page for different manufacturers , go to their home pages and check the details . The average Irish hom,e has a heat demand of around 12 kw , if it is an older less insulated building may be 20 kw . But before going for a bigger boiler go for some extra insulation . And the wider the modulating range the cheaper it is to run the boiler . In most cases something between 4 kw – 12 kw is ideal .

Now I try to get this text in to the AAM and hope there is enough capacity….

.
 
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Re: Conversion to gas central heating

Hi Heinbloed!

Thanks for the thesis. I will print it out and read it carefully.

Thank you for taking the time to explain it in such detail.

Regards

Marion
 
Re: Conversion to gas central heating

thanks Heinbloed, I need to do the same job as Marion and that answer covers all my questions and some I hadn't even thought about
cheers
 
Re: Conversion to gas central heating

That is a fantastic post by Heinbloed it contains just about everything you need to know about gas condensing boilers. In the process of building myself and have just installed one. I can confirm the quietness of the system - hardly audible when running. I do agree it is important to look for models with as full a modulating range as possible. For other self builders where the trend is for bigger houses there are models available which can modulate fully from 3kW to 23kW (mine = ATAG Blue Angel) to give the extra power you may need for the greater than 2500 sq foot house. On the combi boiler side of things I did not go that route as I was not convinced that with the distance to my shower / bath and the possibility of busy times maybe two showers running that the combi could meet the demand. I decided to couple the ATAG up with a rapid recovery hot water cyclinder. The boiler also keeps the underfloor heating and the domestic water flow and return circuits separate (although domestic water gets priority when called for) so there are no conflicts between the low temp needed for UFH and the higher temp needed for shower / tap / bath. The other reason I added the rapid recovery cylinder was that I might decide to add solar tubes (not sure if it would benefit me with an already efficient system - Heinbloed??) to the roof at a later date- the tank I bought is prepared for this addition with an extra coil.

That's my call on it anyway - perhaps interesting for self builders?

BTW - if Heinbloed is not already an energy / environmental consultant he / she should be!!! - keep up the good work.........
 
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