Multi-fuel stove - lukewarm radiators

Gladys94

Hi

Can anyone explain to me what might be happening with my heating system?

I have recently had a multi-fuel stove (Hercules 30B) installed, with a back boiler, in order to provde hot water and serve 12 radiators. This boiler is supposed to be able to deal with 20 radiators.

I also had all our old radiators replaced with new ones and TRVs. The old system was oil, inefficient and incredibly expensive. The point of the new system was to be able to control how much it cost and to have better radiators. All of the pipework is now as it should be with solid fuel.

This is what happens - if we have just the stove on, the flow and return pipes get so hot that you can't touch them. At this point we put on the central heating, and the return pipe immediately goes cold, whilst the flow pipe cools to a lesser degree. Also, as soon as the heating is switched on, the rads get hot, but after a few minutes, they all go lukewarm. I have set all the TRVs to the highest setting - there is no way they could be thinking it's hot, though, as the house is cold!

We have tried this with only one rad (+ heat sink rad, of course), and adding to it, and with all rads on. Also, as the central heating is taking the hot water, the stove itself becomes cooler. Thinking logically, we feed and feed the fire, but practically nothing happens (occasionally a slighter warmer radiator, but not hot).

One annoying thing is that, in order to get central heating, we have to get the 'clock' to ask for hot water as well, even though this is provided by the boiler separately. Could this be the problem, or are we doing something wrong? We will get the company out and they are very nice, but I just want to feel more informed when we do.

Thanks
G

dieselglider

Not really sure about your problem, but have you tried upping the speed on the circulating pump. There's usually three speed settings on the pump.

Always2skint

Hi there!

we also have a hercules 30B for our heating which is connected to 24 or so radiators (not all are normally in use at the same time). We use E7 for our hot water though.

Here is what we have found:

It is best to burn a fuel with a good flame at the front of the stove (just beneath the large pipe inside). This seems to be the quickest way of transferring the heat from the fuel to the radiators. Whilst the radiators never get scorching HOT they do get very warm. I would say that it takes up to 2 hours though to get to this temperature!

Also try opening the vents to increase the burn rate - what fuel are you using?

Good luck!

Always2skint

CWatters_2

Add up the rated power of the rads in KW. Google says the Hercules 30B is rated to provide 20KW to the rads flat out.

thedesignboy

Same problem, just got mine installed and luke warm all over, I've a zoned heating system and a pod that holds hot heating water that heats the cold as needed to hot water?

Please advise, I got the 30b thinking it was 30kw (22kw to heat store).

Help me!
Help me!

crusty_toenail

thedesignboy wrote: »

Same problem, just got mine installed and luke warm all over, I've a zoned heating system and a pod that holds hot heating water that heats the cold as needed to hot water?

Please advise, I got the 30b thinking it was 30kw (22kw to heat store).

Help me!
Help me!

People from Northern Ireland generally have these problems due to bad sales advice:mad: I lived in Whitehead once and it was freezing cold:p Try a 50kw mate.

crphillips

Solid fuel is not an easy thing to plumb. Was it done by a plumber with plenty of solid fuel experience?

You say you switch the heating on? This shouldn't happen as the system should have two pipe stats......one stat turns the pump on when the temp reaches a certain figure and the other turns it off when it drops below a certain figure.....there should be no manual switching to do to turn the heating on. It should be automatic.

It sounds like the pump could be set too fast........slow the pump down......the pump should turn on and off initially to keep the temperature up in the boiler.....once the system gets upto temp it should remain on providing the fire has adequate fuel and air.

I'm always a little sceptical about the kW ratings of the Hercules boilers.....they're a hideous stove.....i never ecommend them to anyone.....usually try and stick with Dunsley or and aarow SEB20.

TRV's are not a good idea on a solid fuel system either as it will upset the whole balance of the heating system. The ratio of heat to direct room heating and to the boiler is crucial.

stingray30

Hey guys, recently have had 25kw stove fitted, rads luke warm at best, pump set at 50 and only camos on for bout 15 secs, tried switching off downstairs rads as its old house with drop down heating!

Same result, luke warm upstairs, had different plumber out and he said losing some heat to the oil burner outside,

he said it might be worth getting a motorize value fitted to stop heat going outside,

he closed the value outside so am going to try for a couple of days!!!

He also said to get good heat from stove to open air vents to get good raoring fire!!

Will be sore on fuel for something i got installed to save money on oil!!!!!!!!!!!

Any ideas and tips will be much appreciated!!!!!!!!!

gamston

i have an old hamlet 8 or 10 stove, with an oil burner fitted to the central heating system
17 rads on the system,
if i run just the stove with pump turned off the 3 heat sink rads get warm and the oil burner gets lukewarm (as there are no valves to stop water moving/convection)
with pump on rads get lukewarm only, thats using coal and wood, with just wood there is very little heat in rads with pump on or off
if you put valves/divertors in the pipework to/from oil burner think you would need to add a heat sink rad oil burner side of the valves as a safety outlet.
also think you need to have pump fitted stove side of the valves/divertors