New Stove Trouble Triple Coil Cyl

[Bailie11]

Hi, have installed a new boiler stove. It's a Nestor Martin Stanford 140B. Installed with 1" pipes, 3 speed pump and also stat located near stove.

Linked into existing sytem of 300L triple coil cylinder. We've OFCH & 60 solar tubes. Haven't had oil on since last Fri.

From 9am this morning fire was going & solar generating but rads did not start to get warm until 12 noon. Even at 12 the rads are only reaching cool to luke warm. Was a bit dissapointed after investing so much in this new system.

Noticed last night that the hw cylinder was reading 65 deg but this morning 55. This had been set to dump heat to rads once tank temp reaches over 65.

Looking for advice on where we could be losing this heat & should the rads be getting warmer than this without the oil?

Sorry should add house is 2600 sq ft, 15 rads in total. 8 large, 4 medium & 3 small. Some turned off.

Thanks

 

[Shane007]

Hi, have installed a new boiler stove. It's a Nestor Martin Stanford 140B. Installed with 1" pipes, 3 speed pump and also stat located near stove.

Linked into existing sytem of 300L triple coil cylinder. We've OFCH & 60 solar tubes. Haven't had oil on since last Fri.

From 9am this morning fire was going & solar generating but rads did not start to get warm until 12 noon. Even at 12 the rads are only reaching cool to luke warm. Was a bit dissapointed after investing so much in this new system.

Noticed last night that the hw cylinder was reading 65 deg but this morning 55. This had been set to dump heat to rads once tank temp reaches over 65.

Looking for advice on where we could be losing this heat & should the rads be getting warmer than this without the oil?

Sorry should add house is 2600 sq ft, 15 rads in total. 8 large, 4 medium & 3 small. Some turned off.

Thanks

Firstly, you need to check that one system is not heating up while the other is on, i.e. when the oil is on, the stove itself is not getting warm and vice versa. If it is this will certainly take a lot of heat from the system.

Noticed last night that the hw cylinder was reading 65 deg but this morning 55. This had been set to dump heat to rads once tank temp reaches over 65.

The system should be set to turn on dump at 75C and turn off dump at 65C. If the cylinder is a stainless steel cylinder the heat loss overnight should be approx 5C and if the cylinder is copper, then it should be approx 10-15C or more depending on the insulation.

From 9am this morning fire was going & solar generating but rads did not start to get warm until 12 noon. Even at 12 the rads are only reaching cool to luke warm. Was a bit dissapointed after investing so much in this new system.

Looking for advice on where we could be losing this heat & should the rads be getting warmer than this without the oil?

Sorry should add house is 2600 sq ft, 15 rads in total. 8 large, 4 medium & 3 small. Some turned off.

This could be an issue with the installation. Did you put down a good fire? Why not get the installer back for advice as he will know exactly what he done the pipework.

My money is on if the route to the cylinder is gravity (& it should be) this will naturally grab most of the heat & you will be heating at least 200L of the cylinder with the stove. Heat will always want to take the easiest route. Once the cylinder it at temperature, do the radiators get warmer?

Is the circulating pump on the 1" pipework or is it on the 3/4" pipework to the radiators?

 

[Bailie11]

Thanks Shane,
the oil has been turned off since last Friday so that we could see what the output from this new stove would be.

Cylinder is a new copper cylinder. Will try change it to 75. This tank used to drop by only couple degrees overnight before the stove was installed.

The straightest route which we've gone for with the pipes are is out from the chimney breast to external wall (lagged, insulated & boxed in trunking), straight up along chimney breast to roof, in through attic, straight above hotpress & dropped down to cylinder. In total 4 1/2 lenghts of copper were used.

The pump is located beside the stove on the 1" pipes. It was left on setting 1 with a pipe stat for 35 degs to make pump kick in.

Rads are only getting to luke warm when cylinder is at the 65. Fire was burning well for a few hours, couldn't leave your hand on the stove.

I will give the plumber a call but weren't sure if this could be something on our side.

Really appreciate your help

 

[Bailie11]

If you really want to make your room warm then you should choose chimney balloons for your chimney. They are easy to install and very effective in stopping the cold air to come down from chimney.

Thanks Jason, the room or chimney isn't the problem.

 

[Shane007]

The straightest route which we've gone for with the pipes are is out from the chimney breast to external wall (lagged, insulated & boxed in trunking), straight up along chimney breast to roof, in through attic, straight above hotpress & dropped down to cylinder. In total 4 1/2 lenghts of copper were used.

The pump is located beside the stove on the 1" pipes. It was left on setting 1 with a pipe stat for 35 degs to make pump kick in.

Rads are only getting to luke warm when cylinder is at the 65. Fire was burning well for a few hours, couldn't leave your hand on the stove.

I will give the plumber a call but weren't sure if this could be something on our side.

Really appreciate your help

The pipe stat should not be set to 35C as when the fire cools down, the circulating pump will stay going pulling heat from the cylinder and dumping it back in the stove, thus cooling the cylinder to 35C. It should be set to 55 - 60C minimum.

The pump should not be on the 1" pipe at the stove. It should be on the 3/4" pipe to the radiators and the non-return valve on the positive side of the pump. I think this is where your problem is. Pump could also be under-sized. I bet it is only a 25/50 where it should be a 25/60. This should be printed on the pump.

 

[Bailie11]

Thanks Shane, set pipe stat now to 55. This was at 35 because of hearing bubbling at stove during our first burn

Can't see a marking on the pump like this. It's a Heat Merchants HM5-130 5M head domestic circulating pump. This is on the 1" pumping from stove to the copper tank.

 

[Shane007]

Thanks Shane, set pipe stat now to 55. This was at 35 because of hearing bubbling at stove during our first burn

It sounds like you have not got a good natural gravity flow to the cylinder. It should not be bubbling when lit. Try lighting it now with the higher stat temp and see if it still bubbles and make sure that the pipe stat is as close as possible to the flow pipe from the stove (the upper pipe from the stove).

Can't see a marking on the pump like this. It's a Heat Merchants HM5-130 5M head domestic circulating pump. This is on the 1" pumping from stove to the copper tank.

That pump is a 25/50 pump and I'm afraid not a particularly good one. You are better to install a Grundfos 25/60 pump.
Is the pump on return pipe or the flow pipe from the stove?

 

[Bailie11]

I think the pump is on the return, the stat is on top pipe from stove,about 2-3 feet away, which goes up to copper tank, the pump is then on the pipe returning to stove, its situated 2-3 feet from stove. the gravity flow prob isnt the best, its 5.5 meter length vertically and then the same horizontally to get to tank, then the same for the return.

 

[Shane007]

Distance is too long and pump should not be on the primary circuit. I presume there is also a non-return valve on this circuit which will also restrict the primary circuit.

You will need to light a good fire and see if it still bangs before the pump kicks in at 55C.

Secondly, the output of the stove is probably undersized to heat 14 radiators plus a 300 litre cylinder. Is that stove only available with 3kw and 7.5kw boiler options. If you had increased the size of the stove, you will have to prepared to feed it and large solid fuel stoves will certainly need feeding!
It is really a play-off between fuel demand and expected heat.

Many installations are really not suitable for solid fuel back boilers and a solid fuel room only stove are normally better options. The cylinder should be within approx 25ft pipe-run (including bends) of the stove.

 

[Vapona]

I've come across a few up-and-over back-boiler installations just like this stove one and they rarely work well. I'm amazed they work at all, to be honest. I wouldn't be at all surprised if the stove suppliers exaggerated the number of radiators it would run - that's fairly common.

 

[Guest125]

4 and a half lengths of copper just to get to and from the copper cylinder is a lot of 1" copper hence a lot of water to be shifting around the gravity circuit. I know its too late now but was there no easier or more direct way to get up to the cylinder? Straight up through the ceiling maybe? As other posters have said,the primary 1" circuit should never have any restrictions and certainly not be depending on the circulation pump to stop the water boiling in the stove. What happens if you have a good fire going and there's a power cut? On a properly set up system if the water boils it will be dumped into the feed tank and then out the overflow. I wouldn't feel safe if that couldn't happen.