Solid fuel heating nightmare

[saddlerscott]

Hi all. Having an absolute nightmare with plumbing.

30kw fire with back boiler installed on ground floor going up to a header tank in the loft and then back down to a heat store which is located in the garage, slightly lower than the fire.
Initial issues were with the circulation. Rads not getting hot and header tank boiling over through the overflow. We resolved that by putting a pump on the return pipe. Then we discovered an issue with heat leak. During summer, the store is heated with the immersions so no need to light the fire. However, due to the location of the heat store, the hot water was going right back up the flow and I assume into the header tank. The result, hot water didn't last and it was costing a fortune to heat it.
We tried to fix this with a lever valve on the floor for when the fire wasn't being used. This solved the issue of the hot water, but has led to massive pressure in the heat store damaging it.

Now thinking the only resolutions are to maintain a system where the hot water doesn't last (as it was before the lever valve was installed) or relocate the hot water tank (not desirable due to the disruption this would cause).

Any advice on what we could possibly do?

 

[Andydevon]

I am no plumber but you really need a professional review of the system as a whole from what sounds like a G3 qualified (pressure systems) heating engineer. It sounds like a lethal set up at best.

 

[fixitflav]

Is it a new system/new problem? Is there a pump?

 

[polesapart]

You need a HETAS engineer with the relevant "wet" plumbing qualification.

Mucking about with extra valves on the F&R of a solid fuel boiler is seriously inadvisable.

 

[saddlerscott]

Is it a new system/new problem? Is there a pump?

New system. Plumber is a bit stumped aside from moving the whole system. There's a pump on the return but the pump is gravity fed

 

[Exedon]

Detail drawing of what you have including pipe sizes and distances boiler / store / cylinder are apart.
Gravity feed pump? explain !

 

[saddlerscott]

Sorry I meant gravity fed heat store!

Not sure my diagrams would be up to scratch. It's a brand new install from scratch so 22mm pipes. Heat store is about 8m from the fire. Image attached of the heat store

 

[muggles]

Does the installer hold the required qualifications for installing wet solid fuel systems? Looking at your photos and reading your description, I'd suggest that they don't.

It's not permitted to have pumped primaries off a solid fuel boiler, they must rely entirely on gravity circulation. They should also be a minimum of 28mm pipe, and need to rise continuously to the thermal store, which needs to be a minimum of a metre above the heat source. That lever valve is very definitely non compliant too

 

[saddlerscott]

Does the installer hold the required qualifications for installing wet solid fuel systems? Looking at your photos and reading your description, I'd suggest that they don't.

It's not permitted to have pumped primaries off a solid fuel boiler, they must rely entirely on gravity circulation. They should also be a minimum of 28mm pipe, and need to rise continuously to the thermal store, which needs to be a minimum of a metre above the heat source. That lever valve is very definitely non compliant too

Is the distance from the heat source important? There is another place that is at least a meter above but it's even further away from both the fire and the header

 

[fixitflav]

New system. Plumber is a bit stumped aside from moving the whole system. There's a pump on the return but the pump is gravity fed

Did the plumber design the system? Whoever did is responsible for it working properly.

 

[Hugh Jaleak]

I would get someone who knows what they're doing to look at it. At best you currently have a system that isn't working very well.

At worst you could have a potential bomb in the house.

 

[muggles]

Is the distance from the heat source important? There is another place that is at least a meter above but it's even further away from both the fire and the header

Provided the pipes rise continuously from fire to store it shouldn't be a problem

 

[ericmark]

It's not permitted to have pumped primaries off a solid fuel boiler, they must rely entirely on gravity circulation. They should also be a minimum of 28mm pipe, and need to rise continuously to the thermal store, which needs to be a minimum of a metre above the heat source.

This is why it cost so much to fit, my brother-in-law had a reinforced floor on the first floor to take the weight, the system worked great, installed when house built, so cost on the mortgage, moved house, looked at installing the same system, and getting quotes of £24k, simply not worth the cost as a retro fit.

I have looked at wood burners, they look so cleaver, and I asked one simple question, what happens if one has a power cut, and I got no answers, with solid fuel there is no way to fit a temperature switch which will switch off fuel supply, at work we have fuse-able lead bungs, and if they get too hot they melt, and the water runs into the fire, and that also means the driver and fireman lose their tickets in most cases.

With our heritage railway engines, we are not so worried about particular emissions, not much we can do anyway, but in the home we are, so a coke or charcoal fire no problem, but wood or coal, the fire must burn at a set rate, too hot and energy wasted, too cool, and we have particular emissions, so the whole idea is for the burn to heat a water store, then the water store heats the home, this

shows one tank, but in real life it was two, rather large, so also rather heavy tanks, there was a display at the fire to show what the state of the tanks was, as clearly if already hot, don't want to light a fire. I looked at is, and as an electrical engineer I thought hope it never goes wrong, as it was a rather complex system.

My son tried fitting it in a narrow boat, he used two 12 volt pumps, with an auto change over should one fail, it seemed to work OK, but seems it failed the RCD so had to be removed (RCD = recreational craft directive) I know many narrow boats did have aga's fitted, but it seems there is an inherent problem, if one drills ventilation holes in bottom of boat, it sinks! So they should not have solid fuel fires, or gas powered fridges, but look at the old narrow boat,

there was really no other option, but we don't seem to have records of deaths due to gases from fires back then.