Multi fuel stove dilemma/question???

newname

Hi

I hope someone can help me with this query.

I am building a house with 22 radiators divided into 4 zones. I want to put a multi fuel stove into one of the sitting rooms. I only have room for a stove capable of heating hot water and 6 radiators. Some people are telling me that putting a stove of this size into a system with 22 radiators will not be a good idea as the stove's boiler will have to work too hard to heat this system.

My question is; If I only have one zone on at any one time, would this not work well enough i.e. the 6 radiator stove would adequately heat a 6 radiator zone?
Or would the heat from the stove still be sent into the overall system of 22 radiators and be diluted to such an extent that it would be effectively useless?

Thanks

ART6

The boiler can only produce so much heat. It can't "work too hard" as it can only work up to it's maximum capacity. Any heat demand above that will simply mean that the output is cooler than it would otherwise be. So, if you turn on all of your radiators at the same time they won't get very hot. If you turn off all but the six of them you say the boiler is rated for, then they will reach temperature. Boilers have what's called a maximum continuous rating or "MCR". They won't go above that whatever you do.

newname

Hi Art6,

Thanks for the reply, so are you saying that if I have 6 rads on a particular zone then the stove will heat these adequately, but if I tried to heat all 22 rads then they would be luke warm at best, as the stove boiler only has the capacity to heat 6 rads.

RKQ

I agree with Art6. The boiler will heat 6 rads well.
I'm not a plumber but assume its possible via timer or non return valves to transfer heat to 6 rads at a time. Maybe heat 6 rads in living area zone up to 8pm then switch to 6 rads in bedroom zone till 10:30pm etc. Then maybe switch to kitchen rads / zone over night on slow burn.

Either way the stove will provide hot water which will lessen the amount the work the oil / gas boiler has to heat. So you will save on fuel costs.

311

I'm a little drunk and shouldn't be posting but ......

You could always run a separate circuit from your stove to the six radiator cirtuit. Drop the circuit into the live 6 rad circuit from your stove.

You would really have to designate your six rad ciruit first though and seperate it from the other zoned areas.
You could do this by implementing nrv's aswell as your zone valves and add an additional pump to your stove .

Anyways, I'm scargled.

Lol.

bbam

Couple of points come to mind...
Remember that when the litrature quotes 6 rads they refer to 6 5ft singles. Any double rads will count as 2.
Are you sure you dont have room for a larger boiler ?, we were purchasing recently and found a huge range of outputs from relatively similar sizes stoves.

Dont short change yourself by putting in a stove that will be too small for the job.. have your plumber work out the BTU requirments for the zones and compare this to the BTU output to boiler on the stove, if it doesn't match it wont heat the zones....

Cheers
bam

ART6

newname wrote: »

Hi Art6,

Thanks for the reply, so are you saying that if I have 6 rads on a particular zone then the stove will heat these adequately, but if I tried to heat all 22 rads then they would be luke warm at best, as the stove boiler only has the capacity to heat 6 rads.

Sorry for the slow reply -- been busy today. In your OP you said that the boiler was rated for 6 rads, so I ssumed that's what it was although I'm more accustomed to them having a Btu or kJ rating. Either way, the boiler will only produce so much heat and no more. So you could have (say) six rads running hot, 10 running warm, 15 running cool, and 20 almost cold. Also, when you use a lot of hot water from your hot cylinder, the rad will cool down as some of the heat is used to reheat the hot tank.

newname

Hi

Thanks for replies guys.

I would like to put in something bigger if i could but, I have already built the chimney's (but not plastered them yet). It would only be structurally safe to hack out another inch or so from each side. This would leave me with a 690mm wide opening to plaster and fit a stove into. If I allow 50mm for plaster and 75mm circulation around each side of the stove then this would leave me 490mm width for a stove.
So i'm kind of limited as to the size of stove I put in.
The only other option would be to rebuild the lower part of the chimney breast??

baldieman

Hi,
I wouldn't be overly concerned about the size of your boiler unless you have access to a lot of solid fuel. Remember, if your boiler can heat 20 rads you're going to be horsing in the fuel and while the 6 rad machine may not heat 20 rads to the required temp. you will get the KW value (increase in temp of 10 or 20 degs) which your oil boiler doesn't have to do. Zoning is a good idea from the point of view of only heating the required areas. If you're in the middle of building, it's insulation and then more insulation!!