Fuel burning stove with back boiler not heating rads.

T

tt2685

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17
Hi,
My Mother had a solid fuel stove with back boiler installed last year.. From day one there are been problems with it,Leaking at first had to get plumbers back out to put extra tank in attick etc... When these problems where finally solved and we could light the stove properly we discovered that it was not heating the rads(only luke warm on a good day). She has tried different types of fuel etc.. Eventually we got friend of family who is apprentice plumber to have a look and after a lot of looking he said that the wrong size copper pipes were installed 1/4 inch pipes not inch pipes, and there is not enough pressure to push water into rads..After falling out with builder who installed it because he said the stove was not big enough to heat rads(15-20 we were told in shop)and we have 17 rads, my mother is at her wits end because alot of money was spent on it and she still has to use oil heating all the time..Could anyone shed some light on this problem?? Sorry for long post.....Thank you...
 
TT what make and model is the stove?

Ask a plumber to calculate the heat load of all the rads together and see if this is matched, nearly matched or exceeded by the stoves output.

From what you have posted if the stove had an 1" flow and return and the plumber/builder used 1/4" its defo going cause a problem. Also a leaking system fixed by putting a tank in the attick doesn't make sense? Someones feeding you bull.
 
Thanks fmc,
We did the calulating thing and builder said there is not enough heat load for all the rads but man in shop said there is..we tried turning off half of rads to see would it heat up other rads but made no difference..As one of the copper pipes is buried underneath new wooden floors in concrete and there is brick work around other one it will be a major job to change them.there is actually 3/4 inch pipes when there should be inch pipes(sorry made mistake in first post).Will check make and model later in day...Thanks
 
The stove is a Glenmore 12kw by Hamco bought in Dublin Builders provided in Wexford.. What if we just replaced the pipe that is behind brickwork(going up to attic) would this work if it is the pipes.. We have 12 rads in house one is a double..thanks
 
Looks like your stove is a little undersized to accommodate your heating load. You need to acquire the services of a plumbing contractor who is competent in the installation of open vented solid fuel heating systems. The mention of gravity fed open vented systems will send many contractors to the hills as they do not know how to install open vented systems as they are used to the easier closed systems as used on the majority of system boilers that are fitted nowadays.
 
villa 1....I disagree... if you have a good enough pump to pump the water around the house from the stove you would imagine that if the stove was lit in the morning and was top'ed off with coal or turf during the day, the water should be boiling..i would look at what pump you are using... a smaller powered pump would not pump the already boiling water around the house fast enough to heat the rads...
 
A standard three speed pump should be adequate for any domestic heating system. A higher speed pump will create terrible noise and water turbulence in the heating system, especially if radiators/zones are controlled properly by necessary controls. If the system is installed using a balanced system of properly sized pipework there should be no problem with hot water circulation and heat outputs.

A pump with too high a motor speed can lead to pump over problems, leading to extreme amounts of corrosion in open vented heating systems, ie, rotting steel radiators, sludging of radiators and clogging of pipework. I have seen and repaired many systems.

This was a huge problem in the era of the solid fuel wrap around heating boilers and will be a problem with the onset of stove/boiler installations

The solid fuel stove seems to be undersized to accomodate the heating/hot water load and the pipework size and design seems to be wrong.

You cannot depend on a pump to circulate water alone. The design of the system has to be right.

Remember the pump is a circulator not a pressure pump. I do have experience in these matters!!:)
 
How come then that in my own house, which is small with an equally small fire can supply enough hot water to heat 12 rad, 4 of which are double and enough hot water for taps /baths.. it also has a high motor speed. it has not let me down over the last 9 years ?
 
Your system happens to be working, the original poster's is not. I am just giving my opinion and and that should count for something after 35 yrs in the pumbing/heating/training business.
As I previously stated, the poster should get an authority on open vented solid fuel heating systems to advise on the situation. I'm sure that the problems can be overcome with expert advise. The solid fuel system is interlinked with an oil fired system so problems may also lie there.
Never take advice from shops, builders, heating,plumbing supplies etc as they are generally not qualified in the area.
 
Thank you Villa 1 and Vacuum box..Some questions if u dont mind..If the stove is indeed too small to heat all 12rads wouldnt turning off half of these make the other ones heat up?? What problems can accure with fuel stove and oil heating.. Where would my Mother find an expert in stove instulation.. Her water is also not boiling hot it is as de rads luke warm..Alot of money was spent on both the stove and insulation and my Mother is so disappointed with it not working.. Thank you..
 
May i also add that the house is a bungalow..Dont know if this makes any difference but have read on this site of people installing smaller stoves that will only heat downstairs rads...
 
We had the same problem with a stanley range recently. it was only required to heat 6 rads.The fire was ab roaring and the rads were only luke warm. It turned out after getting 3 diff plumbers to look at it that it was plumbed in all wrong. Well worth money to get well established plumber to take a look at it.
 
I agree with Villa, boiler is probably undersized. Very few stoves will heat 17 rads unless you stand beside it and shovel coal into it non stop. However, this is unlikely to be the main problem. Very often these stove's are piped wrong. 3/4" pipes to rad circuit should be ok. If the oil is heating rads, then it is ok.

The problem is at the cylinder and the position of the stove pump. Are you getting good hot water in cylinder from stove?
 
Employ the services of a suitably qualified plumber who has a past catalogue of correct dual central heating installations (oil/gas and solid fuel interlinked). They are out there. Ring/contact his/her previous happy customers!!
The stove should have an unrestricted 1 inch primary circuit between the stove and the dual coil hot water storage cyinder. There should be a seperate heating circuit (3/4 inch as Davy says)) linked to the flow/returns from the oil boiler. The system should be fed from an open 45 litre feed and expansion cistern which is normally sited in the attic roofspace. You cannot connect a solid fuel range/boiler to a closed/sealed heating system. If so if a powercut occurs and there is slow circulation you could be looking at steam generation and a possible explosion!!
There are many more technical requirements for a dual heating system and I don't want to confuse the original poster.
Finally with the onset of more dual systems I fear that there will be many problematic substandard systems fitted as most plumbers these days just do not know how to install efficient dual heating systems as during the mad tiger years they have been conditioned to fitting the very common sealed system boilers and nothing else!!
 
Thank you all for ur information.. I think yous are right in just getting qualified plumber who deals with these types of stoves to come look at it..Was wondering JDoc how much it was to get someone out to look at ur stove and give you quote to fix it?? Thank you
 
First plumber charged 600 to put in the stove, the 2nd didn't charge, he just looked at it and said that the prob was the stove and the 3rd guy charged 800 to take out the stove, change pipes and refit it, his price included pipes he used. The first guy left a bill in the hardware store. Stove is going great now all rads pumping shortly after stove lit. Should have just got a decent plumber to begin with.
 
An undersized stove will always be a probelm and one that gets worse. Imagine the water coming back always cold to the stove this in effect also cools the flame of the fire and the fire burns less efficiently a lot of the time creating sooring and crosete on the boiler surface itself. This in turn means theres even less heat tranfer of the fire to the water so it is perpetually getting worse.
A heat load calculated in Kw or btus is always better than how many rads will it heat.
 
hi can you tell me did you get it sorted as i am having the same problem i have just installed a 30 kw back boiler stove it is only heating 5 rads and they are only warm not hot, the plumber saids it is plumbed right ,am i expecting to much i have paid a lot of money on this and i am so disappointed would love to know your result
 
Get your plumber back. A 30kw stove will heat 5 radiators and loads of hot water and more. Don't take any cock and bull story. If this guy has any pride in his work he should get this stove piping hot leading to an efficient heating system.
Make sure he has installed a 1inch primary gravity circuit for hot water heating and a seperate heating circiut for your radiators. This is not rocket science!!
Before he calls have the stove nicely ticking over with a good establshed fire in the stove. Ask him then where is this heat going:)
 
Hi Villa 1. Thank you for your reply. We were told it would heat 20 radiators comfortably. We have 10 double radiators and we also have zoned heating, it is only heating when one zone is off and they are only luke warm. We have fueled it up to the top with coal, used 2 bags of 40k in two days, to see if it would make a difference, its doesn't. Plumber says all pipes are right, rang manufacturer, maybe its the stove. Waiting for a reply from them.
 
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