Topic: Wetback thermal loss when not in use

Wetback thermal loss when not in use 

We have built a new home with a woodburner directly through wall behind the HWC (500mm). The install I believe has been rushed, not thought through and is not thermal efficient because of the unnessarily lenghty complicated pipework. There was backflow when the fire was not in use. This I have had fixed by putting in a pulse valve but I still think we are losing a lot of conductive heat in the hot water cupboard when the fire is not being used as during the day the fire -> hot out to cylinder pipe is very warm all the way back to the fireplace in the lounge. Is there somewhere I can go for advice as our power bill is excessive and I assume we are heating water and losing it constantly into the cupboard and lounge via a giant copper radiator?

Re: Wetback thermal loss when not in use 

Styrofoam plug cut to fit between wetback and firebox to limit heat loss.

Similarly a strong black plastic bag + cardboard as a envelope mould within the firebox, and use PU spray foam to make a very close fitting plug.

Perhaps only a stop gap measure, but will limit a large proportion of energy lost in the firebox itself and up the cold chimney.

Re: Wetback thermal loss when not in use 

I wonder if they've put a bit of an upward slope on that pipe. I imagine hot water might circulate to the highest point in that case and then heat radiate off.

Re: Wetback thermal loss when not in use 

Get the plumber to come back until it works !!
The consumer guarantees act give you every right to demand a fix.

Re: Wetback thermal loss when not in use 

The pipes leading from your fire to the HWC MUST rise upwards to the entry ports on the cylinder; if this isnt done then the cylinder will reverse syphon into the wetback when the fire isnt going. Ideally the entry ports on the HWC are > 30cm higher than the exit of your wetback. Warm water being lighter than cooler water naturally wants to flow upwards. An upward slope ensures that it wont flow downhill into your fire when its off.

Dont know whom you used for a plumber, but if they dont know the basics then they have no right doing this sort of installation.

The pipes should be covered in high temp rated insulation, normally high temp foam type 15mm wall thickness being the minimum.

Suggest you get them back to put it right.