# How hard to fit thermostatic radiator valves yourself?



## suds (24 Feb 2006)

Hi - we want to fit thermostatic radiator valves to regulate the heat of radiators - I believe this is energy efficient. We got quotes of approx €400 for six radiators, inclusive of valves. Apparently the radiators need to be bled, and this makes it a largish job. Plus most say it would be a few months before they can do it. I wondered if it's a possible DIY job. Can you buy these valves anywhere? Is bleeding radiators difficult? Any advice from those with DIY experience very welcome.


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## BillK (24 Feb 2006)

Someone is pulling your leg if they say that bleeding rads "makes it a largeish job".
You can buy a bleed tool in B&Q or any builders merchants and if takes more than 2 minutes to bleed each rad I would be astonished.


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## NiallA (24 Feb 2006)

The issue isn't that yu have to bleed the rads, it is that you have to drain the water out of the system and then when the valves are fitted, refill the system and then bleed the rads (to get the air out).

I fitted thermostatic rad valves on some of my rads. First, turn off the boiler. Then I needed to attach a hose to the draincock (usually at the lowest point), turn off the water going into the system to stop it from refilling, and then open the drain cock.  Go around the rads to open the bleed valves (small valves at the top) to allow air into the rads and the water to drain out.  When the system is completely drained open the nuts on the valves of the rad and remove the rad from the wall.  on the wheel nut side (the side that you would normally turn off and on the radiator) remove the valve (you could use the other lockshield side, however this is usually used to balance the radiators ie control the heat through the rads so they all get the same heat from the boiler).  The attachment on the rad for the valve needed to be changed to suit the thermostatic rad valve, The whole lot can then be reassembled.  When that is done on all the radiators, you can close the draincock, thurn back on the water and le the system fill up.  As all the air goes out of each rad close the bleed valves.  In a couple of days teh rads will need to be bled again to remove any air that has settled after the system was running for a while.


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## beldin (25 Feb 2006)

Just to add to the previous post. In my case I needed an allen key to take the fitting out of the radiator. What I did was similar except that I just disconected the valve on the side I was taking off , and left the radiator on the wall.  It made for a much easier and cleaner job. 

I just disconnected the valve from the radiator and then removed it from the pipe, this gave enough room to remove the fitting screwed into the radiator.
Removed this and replaced it with the new fitting wrapped with tape..
Put on the new valve and screw everything back together. 
Also get an old sheet and wrap it around the area you are working as the water that will drip out is foul and will stain everything.
this is fresh in my mind as I did 3 yesterday.


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## Carpenter (25 Feb 2006)

I fitted 7 TRVS and new lockshield valves in my house last year.  The job took a whole day as I also took the opportunity to flush out each rad.


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## z102 (25 Feb 2006)

Someone is trying to rip you off, Suds. A radiator valve (thermostatic) costs around €10-20, if buying 6 of them you'll get a "family"-pack making them even cheaper. Changing a radiator valve is the typical DIY job, check Collin's DIY book for complete advice, the plumbing section of Collin's DIY book can be bought seperatly for just €6-8. Good luck.As Carpenter says: max. working time would be about a day for the untrained person incl. breaks. When buying the valves buy the suitable spanner as well, size 27 as far as I remember, plus a plumbers plier and a roll of teflon tape and a bleeding "key". Tools cost around €10-20 , the tape a few cents. Go for quality valves, the very cheap ones can have a to slow reaction. Keep the boxes and the small brochures that come with it until you know they work properly. And they should work from the first day, otherwise you have done something wrong (maybe the person who gave you the quote did it always wrong and is not used to see a proper job done the right way).
You have to equalise the flow of the radiators after putting new valves into the system, I think Collin's DIY will tell you as well how to do that. Otherwise check the previous posts here on AAM, see "UFH" .


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## NiallA (26 Feb 2006)

Heinbloed,

I'm not sure about the rip off.  €400 less vat, (€47) 
less cost of valves (6x €15 say) leaves the job costing approx 32 euro an hour.  For a tradesman to pay insurance, pension etc out of that, doesn't leave much IMHO that can be considered a rip off.


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## suds (27 Feb 2006)

Thanks all. It sounds like a bit of work, but fairly doable as well. I'll see what himself thinks, and maybe we'll we'll tackle it one of these weekends. I agree that it is probably not a rip-off - tho' not cheap - as when you break down the cost of valves, labour, vat etc, it's probably what most places would charge. Thanks. S.


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## beldin (27 Feb 2006)

One other point is not to put TRVs on all radiators , one radiator has to set as normal so that the boiler doesn't overheat if all the radiators are turned off.


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## ribena (27 Feb 2006)

I had a plumber in a couple of weeks ago pricing a job for me.  I asked about fitting TRV's.  He said it was €10 per rad but if I was getting another job done, they wouldn't charge.


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## z102 (27 Feb 2006)

€10 per radiator is a more realistic price. €32 per hour -- fine if the man can do 5 TRVs per hour. Calculating a days wage on the capeabilitys of a DIY person is hard to justify. 
All radiators can be fitted with a TRV, Beldin's advice to leave one radiator without TRV is wrong. I lived in dozens of homes and flats where all radiators had been equipped with TRVs, no problem. A boiler that is not equipped with overheating protection is simply dangerous and illegal, a radiator without TRV would in this case be of no help. Since a boiler would-when overheating- produce steam. That could cause an explosion in a closed system or an overflow with an open system. Any boiler available in the EU would have at least two safety features to protect against that : a temperature sensor and a pressure sensor. For more safety modern boilers have some safety features twice (at different points of the system), but that would be for very large heating systems, feeding entire apartment blocks and the like.


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## owenm (28 Feb 2006)

Which side of the rad should the TRV be on ? Without TRV's the on off valve side is irrelevant but with TRV's it becomes important I think??
i.e. TRV on Return or inlet side?

Tks,


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## Carpenter (28 Feb 2006)

owenm said:
			
		

> Which side of the rad should the TRV be on ? Without TRV's the on off valve side is irrelevant but with TRV's it becomes important I think??
> i.e. TRV on Return or inlet side?
> 
> Tks,


 
Most TRVs are now bi-directional and can be fitted on flow or return.


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## z102 (28 Feb 2006)

And the height at which point you connect it to the radiator is also of some importance. If having an uninsulated floor (downstairs) and putting the valves at the bottom of the radiators you would make them slow and wrong to react. Since the thermostat will get the temperature from the cold floor (the air that rises up at the radiator is "pulled" over the cold floor first) you could end up with a valve that is not at all (themostatically) reacting. In this case you buy a valve with a sensor that can be fixed to the wall wherever you like, usually 60-120 cm above ground, read the instruction manual. This temperature sensor is connected to the valve either by a thin cable (mind the playing cats and toddlers) or it is sending signals to the valve by infrared or radio waves. Similar to the remote control of your TV set.


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## bMino (1 Mar 2006)

Hi - I will be doing this soon but have no plumbing experience so sorry in advance for the stupid questions.

Where is the Draincock located......is it on the Radiator ?  And how do you turn off the water going into the system ?  Is it by using the regular off and on connection on the radiator.

If I turn off boiler, turn off the radiator with the connection on the side, drain the radiator, open the bleed valves to allow air in, surely when I remove the valve water will come out of the system or how does this work ?

Do you turn off the water to the whole house before you start or drain the cold water tank in the attic ?


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## Carpenter (1 Mar 2006)

bMino said:
			
		

> Hi - I will be doing this soon but have no plumbing experience so sorry in advance for the stupid questions.
> 
> Where is the Draincock located......is it on the Radiator ? And how do you turn off the water going into the system ? Is it by using the regular off and on connection on the radiator.
> 
> ...


 
Are you sure you should be attempting this job yourself, when you have no plumbing experience?  As a starting point you should really get Collins "Guide to plumbing and central heating" before you start any work on your heating system.  As for draining down the heating circuit- it all depends.  The original installer may have fitted drain cocks on the primary circuit to allow you do drain down the system.  In my case he didn't so I loosened off the two plugs on the boiler and allowed the water to drain away.  You can work on the heating circuit in isolation without affecting the rest of the house's water supply, providing you can cut off water supply to the feed/ expansion tank in the attic- either by turning off the gate valve (if there is one) or tying up the arm of the float valve.


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## owenm (1 Mar 2006)

Agree with carpenter, I'm only a half baked plumber but you frighten me.


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## NiallA (1 Mar 2006)

heinbloedA boiler that is not equipped with overheating protection is simply dangerous and illegal said:
			
		

> Solid fuel heating systems are like this, not illegal, infact very common.  One rad should be left open at all times, so should not be fitted with a TRV.


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## z102 (1 Mar 2006)

True , Nialla, I didn't cosider the "gun pipe above the open fire" to be a central heating boiler. Modern solid fuel boilers (those that are build within the last thirty or forty years) come with overheating protection, as much as gas or oil boilers.
Even the old backboilers have an overheating protection, the expansion tank. Leaving a radiator open is no safe overheating protection. A radiator would deliver/let out only a certain amount of energy. If the backboiler produces more heat than the open radiator lets out we would be where we started - without a safety rope. Therefore the expansion tank is attached to the open backboiler system as a legal must.
If it was dangerous to run the backboiler system without a valve open on one radiator then there shouldn't be a valve fitted to at least one radiator.To avoid accidents.This legislation-that one radiator should be without a valve- does not exist. Because it is not necessary. The safety aspect is fully covered by the expansion tank.
So there is no need to keep a radiator without a (thermostatic)valve.No matter what boiler is delivering the energy.


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## Carpenter (2 Mar 2006)

heinbloed said:
			
		

> True , Nialla, I didn't cosider the "gun pipe above the open fire" to be a central heating boiler. Modern solid fuel boilers (those that are build within the last thirty or forty years) come with overheating protection, as much as gas or oil boilers.
> Even the old backboilers have an overheating protection, the expansion tank. Leaving a radiator open is no safe overheating protection. A radiator would deliver/let out only a certain amount of energy. If the backboiler produces more heat than the open radiator lets out we would be where we started - without a safety rope. Therefore the expansion tank is attached to the open backboiler system as a legal must.
> If it was dangerous to run the backboiler system without a valve open on one radiator then there shouldn't be a valve fitted to at least one radiator.To avoid accidents.This legislation-that one radiator should be without a valve- does not exist. Because it is not necessary. The safety aspect is fully covered by the expansion tank.
> So there is no need to keep a radiator without a (thermostatic)valve.No matter what boiler is delivering the energy.


 
May not be a requirement to keep one rad without a TRV but it does provide a useful heat sink, allowing excess heat to dissipate.


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## z102 (2 Mar 2006)

Creating excess heat is a waste.It wastes money, resources and the health of the community which has to bear the smoke from an open fire. So to speak it wastes OUR money. Why should we support that with a nodding to the ignorant usage of energy ?!


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## Carpenter (3 Mar 2006)

Anybody else care to respond to the last post?


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## Leo (3 Mar 2006)

Pass! Sure we're all backwards here anyway...


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