Wood Burner with back boiler - heating installation questions

Firstly the wood burner is being installed by a qualified HETAS engineer, so that is all under control.

It will be used to drive the central heating system and hot water.

My questions relate to the plumbing side.

I already have a hot water cylinder plumbed in to give hot water through electric heating. It is an indirect cylinder and I have the indirect coil plumbed "ready" for the woodburner.

However, looking at various web sites there seems to be a requirement for a radiator in the indirect circuit to act as an additional load (minimum 1kW). Does this radiator have to be at the same height (more or less) as the cylinder or can it be lower? The reason I ask is that (as you would expect) the hot water cylinder is upstairs but I would like this "load" radiator to be downstairs.

Second question.

What is the physical make up of the back boiler? There are 4 tappings - two for the hot water circuit and two for the heating circuit - are they "commoned" inside" (it is not clear from any drawings or explanation).

Again, the reason I ask is that I have all the feed and expansion tanks set up for the indirect hot water, when that is connected to the heating, will the heating share the same feed and expansion or do I need another tank in the loft!

Finally, is there a "best" place for the central heating pump? It is shown in schematics as being in the return leg of the heating system, but does it have to be next to the boiler or can it be a distance away?

Thanks in advance.

Peter

Reply to
Peter Sheppard
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The four outlets are all commoned to the one water jacket. There should be two near the top and two near the bottom of the jacket.

On my Bont ESSE Model Four I used the left hand two for the indirect heating loop in the hot water cylinder. The top outlet to go to the top of the heating loop and the bottom outlet of the jacket to the bottom of the heating loop. The right hand pair of outlets were used for the central heating (CH) circuit. The top (Hot) outlet had the circulation pump fitted to it so that the pump pushed the hot water out to the radiator circuit. The return (Cold) pipe went into the lower outlet of the water jacket.

The cold water feed from your small 4 gallon header tank can connect to the same pipe as goes to the bottom of the water jacket or the bottom of the indirect heating coil.

My 'Leak' or 'Dump' radiator, which is not pumped, is on the same level at the Bont ESSE. The cylinder is one floor up from the Bont ESSE. The 'dump' radiator is effectively across the indirect heating coil except in my case the cold, return from this 'dump' radiator, returned to the pumped return pipe of the CH system. The reason for this was because the cooler water output of the 'dump' radiator will not go back up-hill to the indirect coil as that is virtually where it came from in terms of water height.

Sit down and draw it. Remember the priciple of a 'U' tube, you can NOT have a radiator higher than your 4 gallon header tank.

Chris.

Reply to
mcbrien410

I appreciated you have already committed yourself to this configuration but I will warn you, based on experience, that it does not work whatever the stove seller says.

The problem is that the amount of heat you require to drive the CH system requires the stove to be driven hard, and because the water jacket does not totally encapsulate the flame as in a gas or oil burner, there is a large amount of heat leakage with the result that the room the stove is in gets uncomfortably hot. I considered using hot air extraction and circulation to get round this but in the end opted for an oil burner with the wood stove operating in parallel through a mixer tank.

I will admit that I have never bothered with a bleed radiator and in 25 years have never had a problem.

Rob

Reply to
robkgraham

Rob, you could be right about the 'Bleed' or 'Dump' radiator in normal situations but back in the 1983-84 Winter "We" had no electricity for nine days and my dump radiator was the only one working. I was giving hot water away to the neighbours and throwing it down the drain. After three days when the house started to cool right down I moved my bed next to the dump radiator and was glad I had installed it.

Our lounge, with the Bont ESSE in does get real warm............... nice.

Aberdeenshire and 24 inch think Granite walls.

Chris.

Reply to
mcbrien410

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