Solid fuel central heating problems

[Nostrum]

Anyone's guess.

can you just clarify a few things. Oil boiler was existing, solid fuel added after? Does the oil boiler still heat a hot water cylinder?

If yes to all, take some photos of the oil boiler heating pump and pipe work around that area and post them up.

 

[nehie]

Anyone's guess.

can you just clarify a few things. Oil boiler was existing, solid fuel added after? Does the oil boiler still heat a hot water cylinder?

If yes to all, take some photos of the oil boiler heating pump and pipe work around that area and post them up.

No, there was a solid fuel Rayburn there for about seven years or so, which worked perfectly. Then, in 2007, we added this new stove (in a new extension to the house) and put in an oil burner too. The oil burner, as I understand it, heats one of the coils in the dual-coil cylinder. We hardly ever use it though because we can't afford the oil.

I'll try and post photos tomorrow. Thanks all.

 

[Simon F]

All the pipework is hidden really, but here's a picture of the stove, with two one-inch pipes coming out of it. After about 50cm on the horizontal, one of these pipes goes up into the attic and the other goes down into the floor. There's quite a distance between the stove and the cylinder - about 30 feet to walk it.

are the pipes 22mm or 28mm, look like 22mm!
what provision is there for gravity circulation, ie a heat leak radiator?
what happens if the pump is not on??

 

[nehie]

are the pipes 22mm or 28mm, look like 22mm!
what provision is there for gravity circulation, ie a heat leak radiator?
what happens if the pump is not on??

Their circumference is a little under 9cm, giving a diameter of 2.8cm by my reckoning. The stove is bigger than it looks in the photo.

I just don't know if there's a gravity-linked radiator. What happens when the pump is not on is exactly the same as what happens when the pump is on - banging and clattering and a spewing of precious hot water into the open air.

I'll do a properly strict test on the stove tomorrow, lighting it on its own, so I can be absolutely exact with these answers. I'm so immensely grateful for all this expert advice and questioning. Thank you.

 

[Nostrum]

So the position has changed from the existing rayburn position. Where is the pump in relation to the stove?

Presumably if you have a twin coil the circuits are hydraulically separate, do you have 2 small tanks in the loft or where ever along with 1 large tank for the hot water?

 

[nehie]

So the position has changed from the existing rayburn position. Where is the pump in relation to the stove?

Presumably if you have a twin coil the circuits are hydraulically separate, do you have 2 small tanks in the loft or where ever along with 1 large tank for the hot water?

The pump is next to the hot water cylinder, so it's a good distance from the stove - about 30ft to walk, and I don't know how many feet of piping would be involved... It goes upstairs and then back down to the cylinder.

I'm ashamed to say I don't know how many tanks are in the loft. But I'll see if I can have a look tomorrow. I do truly wish plumbing wasn't such a mystery to me!

Just want to add as well that the thermostat is above the stove - it's not next to the pump. But as I said you can override the thermostat and turn the pump on manually.

 

[diamondgas]

Just want to add as well that the thermostat is above the stove - it's not next to the pump. But as I said you can override the thermostat and turn the pump on manually.

what sort of thermostat are you talking about here nehie? Is it attached to any of the pipes from the back of the fire? Not that it really matters if you can override the pump and still nothing works!!

Have any of the plumbers you've had done anything with the pump?

 

[nehie]

what sort of thermostat are you talking about here nehie? Is it attached to any of the pipes from the back of the fire? Not that it really matters if you can override the pump and still nothing works!!

Have any of the plumbers you've had done anything with the pump?

The thermostat is in a little attic cubby upstairs. I don't know how it's connected to the stove. In the old system, with the Rayburn, there was no thermostat - you just flicked on the pump when it got hot. So this was put in afterwards - for the stove only, or for the stove and the oil boiler, I don't know.

The second plumber's only action re the pump was to reduce the temp on the thermostat so the pump would kick in sooner. Took him half a day to arrive at that proposal and needless to say it didn't help. This is why I'm pestering you all here on this forum; I really want to have a better idea of what's going on the next time I get someone in.

The first plumber (he was the one who installed it, and came back when i rang him about it) seemed to think the system was airlocked. To be honest I can't even remember what he did. If it helped, it only helped for very short time because I can never remember this working properly.

 

[diamondgas]

If the pump is designed to kick only when hot then the circuit is gravity. An airlock is a possibility.. There is a chance that the pump is doing little or nothing to assist circulation if there's a lot of air trapped in the gravity circuit. It may well be just circulating water around the radiators, bypassing the boiler all together The take-off for the pump is crucial if it is to be of any benefit in assisting the removal of the heat from the boiler.... You use to be able to get something like an injection tee or swepped tee that would aid the gravity circulation when the pump was operated ... It's been a long time since I've had much to do with gravity circs.... Not sure if they're still available or in use and whether something such as this would help the circulation TBH! Depends on the severity of the restriction ...

 

[nehie]

If the pump is designed to kick only when hot then the circuit is gravity. An airlock is a possibility.. There is a chance that the pump is doing little or nothing to assist circulation if there's a lot of air trapped in the gravity circuit. It may well be just circulating water around the radiators, bypassing the boiler all together The take-off for the pump is crucial if it is to be of any benefit in assisting the removal of the heat from the boiler.... You use to be able to get something like an injection tee or swepped tee that would aid the gravity circulation when the pump was operated ... It's been a long time since I've had much to do with gravity circs.... Not sure if they're still available or in use and whether something such as this would help the circulation TBH! Depends on the severity of the restriction ...

Is it a difficult task to get rid of an airlock? Have been swotting up on injector tees - I don't know if there's one in the system. I also don't know which radiator (if any) is gravity-fed because to find that out I'd presumably have to disable the pump, and I'm a bit afraid to... Should I? If I turn the pump off and turn the thermostat way up, to keep it off, will that tell me?

 

[nehie]

Presumably if you have a twin coil the circuits are hydraulically separate, do you have 2 small tanks in the loft or where ever along with 1 large tank for the hot water?

Left out this bit of your question Nostrum: as far as I know, one of the coils is for the oil boiler and the other is shared by the two solid-fuel devices. I think there's only one small expansion tank in the attic, and a header tank. Can't be sure of that though. YOu can't get up there - the tank is in the way!

 

[diamondgas]

Is it a difficult task to get rid of an airlock? Have been swotting up on injector tees - I don't know if there's one in the system. I also don't know which radiator (if any) is gravity-fed because to find that out I'd presumably have to disable the pump, and I'm a bit afraid to... Should I? If I turn the pump off and turn the thermostat way up, to keep it off, will that tell me?

All it takes is a crest/dip in the pipework somewhere and air will trap stopping/slowing down the circulation. I'm assuming the pipework goes up and over then drops down to the cylinder, returning underfloor to the boiler position. Anywhere on that circuit is a potential air trap and/or sludge trap? Turning the pump off will only make things worse in my opinion!

Regards removing an airlock, it can prove nigh on impossible especially if it's in the return under the floor!!! If you don't have an injection tee fitted then it may be the lease expensive step to take in having one installed and seeing if that resolves the issue?

 

[hitch61]

It sounds like the install is to blame It would be nice to see how the two heat sources are are linked. Usually best done trough a dunsley nutrulizer or similar

 

[Lou]

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