A multi fuel stove for water heating?

[Phil Pascoe]

I have a problem that I cannot see should be insurmountable - how do I fit a boiler and tank in a bungalow? I have only had one person look at it so so far, but he said it cannot be done as the pipework has to run into the roof space and back down to the boiler. I contacted Steve Dowling (Dowling Stoves) for advice, but he non committal, saying that in an ideal world the pipework would rise and fall straight from the stove to the tank - which is of course obvious - but how many instances is this possible? The heating guy to whom I spoke said it would be illegal to have a pumped system from an unregulated heat source, which makes some sort of sense although it would have to vented (for safety) whether or not pumped. The original page on Dowling's site said that a hot water system did not need to be pumped, but a central heating system did - why would it be legal to pump in one system and illegal to do so in the other? They must both carry some risk?
I cannot imagine that it it is impossible to fit fit this type of water heating in a bungalow, which it would be in 99% of them - how many bungalows have an airing cupboard and tank next to boiler? I've never yet seen a notice on a stove in a showroom saying "This stove is not suitable for water heating in a bungalow", and it is going to seriously pee me off if I can't do it, as it was a major reason I bought the stove and £100+ down the Swanee for a boiler I can't use.

Thanks for any advice, though please be aware I'm only interested in what can be done legally, not what it is actually possible to do.

 

[RobinBHM]

I think megaflow systems are used in these sort of applications, but I only know about wood so cant be more help, Im sure a heating engjneer will be alkng soon.....

 

[sunnybob]

youre not clear what type of boiler.
The tank thing (un pumped) would normally be an expansion tank to allow the heated water to expand freely and the hot air vent into a roof space. Does you bungalow not have a roof space at all?
The unregulated heat pumped system would be extremely dangerous, if the fire got very hot the water would turn to steam inside the pipework and then you would have a shrapnel bomb in your living room.
It is possible to fit over pressure release valves, but then you would need an automatic refilling system the replace the hot water spewing out of the roof every time you banked the fire up.

You need to ask around, presumably your neighbours are in bungalows? how do they manage?

 

[nev]

See the last 2 paragraphs at the bottom of the page here...
http://www.gr8fires.co.uk/articles/stov ... al-heating

 

[Phil Pascoe]

Bob - a boiler in a multi fuel stove. I don't want to put the hot water tank in the roof, for one because of heat loss, and for two because I would then have to find somewhere even higher for the cold water tank, and three, obviously - the cost. My neighbours all have bottled gas.
Nev - did you mean a particular page or the comments?

 

[Woody2Shoes]

Hi - this is something I've looked at in some detail in the past. An uncontrolled heat source (which is what we are talking about), must be able to "dump" a very significant volume of heat (to avoid heating any water above boiling point) at all times, regardless of the presence of electricity i.e. it must demonstrably "fail safe" not " fail dangerous".

On our multifuel, back-boilered, Rayburn we have a an upstairs tank, gravity-fed by large 28mm pipe runs, not vertically above, but to one side with swept bends and sloping pipework for efficient thermo-syphoning. We also - per the manufacturers instructions - have a decent-sized rad (in the bathroom) permanently in this loop. We also have a small electrical pump feeding a couple of extra rads (the rads are on a physically separate, but hydraulically linked circuit using a special kind of tee valve the name of which escapes me). This works well - but I wouldn't want to feed this set-up with wood (I'd get no rest) - coal keeps me busy enough!

So, you can use pumped circulation as part of your solution, but you do need a large body of water to buffer large amounts of heat if you and/or electrons are not available to assist in regulating the system. It seems difficult to do this safely without some kind of gravity-fed tank (which I suppose doesn't need to be more than a foot or two above the boiler).

Cheers, W2S


PS I remember, when reading about thermal stores, that a tank can be physically alongside the boiler - just as long as there's a proper thermo-syphon linking the two.

 

[paulrockliffe]

I've looked at this before, the only way to really do it safely is to be able to remove the thermocoupling to stop the heat entering the system. But even that's very difficult to make fail-safe.

Alternatively you could change tack and pump hot air, that would be pretty cheap and would work well I'd think.

I've considered pumping air in our house, we have 9' ceilings so a lot of heat sits above your head, we get decent heating upstairs from heat going up the stairs, but it's not perfect. Yet we have the 4 main rooms all meeting at the top corner of the heated room, so would actually be quite simple to add a pump and some ducting. It's annoying that I didn't think of this when I renovated the house as I could have fitted hot air ducting to the cold bathroom at the time.

 

[Jacob]

Hi - this is something I've looked at in some detail in the past. An uncontrolled heat source (which is what we are talking about), must be able to "dump" a very significant volume of heat (to avoid heating any water above boiling point) at all times, regardless of the presence of electricity i.e. it must demonstrably "fail safe" not " fail dangerous".

On our multifuel, back-boilered, Rayburn we have a an upstairs tank, gravity-fed by large 28mm pipe runs, not vertically above, but to one side with swept bends and sloping pipework for efficient thermo-syphoning. We also - per the manufacturers instructions - have a decent-sized rad (in the bathroom) permanently in this loop. We also have a small electrical pump feeding a couple of extra rads (the rads are on a physically separate, but hydraulically linked circuit using a special kind of tee valve the name of which escapes me). This works well - but I wouldn't want to feed this set-up with wood (I'd get no rest) - coal keeps me busy enough!

So, you can use pumped circulation as part of your solution, but you do need a large body of water to buffer large amounts of heat if you and/or electrons are not available to assist in regulating the system. It seems difficult to do this safely without some kind of gravity-fed tank (which I suppose doesn't need to be more than a foot or two above the boiler).

Cheers, W2S


PS I remember, when reading about thermal stores, that a tank can be physically alongside the boiler - just as long as there's a proper thermo-syphon linking the two.

Large thermal store could be an answer; the system instead of being able to dump heat as a safety measure, has enough storage in the system to absorb worst case over-heating.
This also means you can do batch burning i.e. smaller charges of fuel burnt fast with plenty of air, which is more efficient than the opposite, but might over-heat a more conventional set up
So double benefit; efficient burning and efficient heat storage

 

[Woody2Shoes]

Yes - the only downside to having the buffer tank/thermal store physically alongside the boiler is that - to get hot water to flow out of it - you'll probably need an extra heat exchanger/tank coil and a pump (the advantage, if done correctly, is mains-pressure hot water) the disadvantage is additional cost and the amount of space that the tank needs in your living space. Cheers, W2S

 

[Woody2Shoes]

This company has been doing these kinds of system for a long time. There are clearly all sorts of (quite expensive) variations on the theme. They seem to offer a fully pumped system from a woodburning source - I think it would have to be carefully designed/sized to be 100% safe! Cheers, W2S

http://www.heatweb.co.uk/products/ds15/

 

[david123]

I'm in Devon. I had a guy put in my woodburner that also runs a couple of radiators. I had a few quotes and lots of sucking of teeth and staring at the heavens. In the end I contacted this guy on the recommendation of a friend in the village. He wandered in, no problem very reasonable quote and did a brilliant job and as a HETAS engineer he was also able to sign it of.
I was very impressed with the quality of work and his understanding of heating systems. I also got him to change our old central heating boiler and put in a new water cylinder that would take the excess power from our solar panels to heat it. As he had already done it for another customer he was well up to spec on what was needed.
He may be able to advise you. Pm me if you want his number.

 

[Phil Pascoe]

That at least proves my man wrong - he insists that any pumped system is illegal. I can't quite see why a pumped central heating system seems to be OK - but a pumped hot water system not so.
I haven't the option of putting the tank in the same room as the boiler, there just isn't the space.
David, thanks. I'm hoping to be able to find someone local who has a bit more knowledge than the eejit to whom I spoke. He didn't even have the courtesy to get back to me.

 

[david123]

Wish you luck with that, hope you get it sorted.

 

[nev]

...
Nev - did you mean a particular page or the comments?

the last two comments. Seems by this reply that there are sealed/ pressurised systems available?


celia frampton 2013-11-06 20:24:43
I live in a bungalow and have no chimney. Would I be able to have a a log fired full Water and
heating system?? Regards

Gr8Fires.co.uk 2013-11-23 11:05:11
Hi Celia, Yes, you can use a Stratford Ecoboiler boiler stove to run your heating system, and
install a twin wall flue system for a chimney. The Ecoboilers can operate with a pressurised hot
water system. Just give us a call on the number at the top of the page if you need more
information. Thanks, Gr8Fires

 

[Dee J]

The big issue is... If you have a pumped circuit from the boiler to the tank, and your fire is burning good and hot... And then for whatever reason the pumping fails. Regardless of laws and regulations there remains the basic physics of a lot of heat and steam to be dumped. A boiler full of water makes a lot of steam. There may be technical work-arounds, but they won't be easy or cheap.

 

[Phil Pascoe]

Thanks, Nev - that's what I thought you were referring to. I shall have to see if I can find what is so special about a "Stratford Ecoboiler".
Dee J - I know what the dangers are, what I'm really trying to ascertain is why a hot water system won't work unpumped - apparently it heeds a pump to run central heating but not to run hot water (although the page on the Dowling site that said that seems to have been removed :? )

My pipework would run upwards for 6 feet, across the roof space for about eight feet then down to the tank. It's not hundreds of feet. I'd have thought although it wouldn't start instantly once it started it would run under its own gravity?

 

[Phil Pascoe]

There doesn't seem to be any information as to what is different about the Stratford boilers, other than that they have some form of thermostat and they can be fitted in a central heating system.

 

[Dee J]

Thanks, Nev - that's what I thought you were referring to. I shall have to see if I can find what is so special about a "Stratford Ecoboiler".
Dee J - I know what the dangers are, what I'm really trying to ascertain is why a hot water system won't work unpumped - apparently it heeds a pump to run central heating but not to run hot water (although the page on the Dowling site that said that seems to have been removed :? )

My pipework would run upwards for 6 feet, across the roof space for about eight feet then down to the tank. It's not hundreds of feet. I'd have thought although it wouldn't start instantly once it started it would run under its own gravity?

No option of putting the hot tank in the roof I suppose?

 

[Graham Orm]

That at least proves my man wrong - he insists that any pumped system is illegal. I can't quite see why a pumped central heating system seems to be OK - but a pumped hot water system not so.
I haven't the option of putting the tank in the same room as the boiler, there just isn't the space.
David, thanks. I'm hoping to be able to find someone local who has a bit more knowledge than the eejit to whom I spoke. He didn't even have the courtesy to get back to me.

Because if the pump stops working it forms a blockage and with no thermostat to shut down the heat source.......kaboom!

On a heating system the thermostat will turn the boiler off if the water stops flowing and the boiler overheats.

 

[Phil Pascoe]

I'm talking of a radiator system from the multi fuel, not a thermostatically controlled boiler. The original Dowling page said it would have to be pumped - I'm wondering why that would be OK, when pumped hot water wouldn't be. Last I looked I couldn't see the page - maybe it was taken down as being wrong.

I could put a tank in the roof, but I don't want to, for one it would be very difficult to put a cold tank higher and for two because of added expense and inefficiency.