Solid fuel central heating problems

[nehie]

Hello. I just want to see if anyone has any ideas about an ongoing problem with a solid fuel stove with back boiler. When it gets hot, instead of heating the radiators, it just spills hot water out of the expansion tank outlet in the outside wall of the house. That's even with the pump running. It's a 16KW stove and should heat several radiators. Thanks in advance.

 

[diamondgas]

:welcome: to the forum nehie

Are your radiators turned on? Does your heating work otherwise when turned on?

 

[SimonG]

New install?

 

[nehie]

:welcome: to the forum nehie

Are your radiators turned on? Does your heating work otherwise when turned on?

Yes, the radiators are on! We have an oil boiler as well, which seems to heat the radiators efficiently enough, although there's a small trickle from the expansion tank even with that - though nothing like what happens with the stove

 

[snowhead]

Assuming not a new install and previously proven to work:

Bad or no circulation.

Is the pump powered and "running"?
Or is the pump impellor spinning and moving water?

If it's a new, not proven install, it now wants looking at by someone who knows what they are doing re design of systems.

 

[nehie]

New install?

No it's been there for over five years now and has never worked properly. Two plumbers have looked at it but not diagnosed the problem. The first thought it might be airlocked; the second suggested lowering the temp on the thermostat, so the pump would start up sooner, but that didn't help.

 

[nehie]

Assuming not a new install and previously proven to work:

Bad or no circulation.

Is the pump powered and "running"?
Or is the pump impellor spinning and moving water?

If it's a new, not proven install, it now wants looking at by someone who knows what they are doing re design of systems.

Pump seems to be working OK (I think) as it also serves a solid-fuel range in the kitchen. Can't say if it's the right pump or not, or powerful enough.

I agree about getting someone to look at it but haven't been able to find anyone competent so far (see my previous post re two plumbers).

 

[SimonG]

Sounds like its not been put in right. Whereabouts are you, maybe somebody on here close enough to have a look.

 

[nehie]

Thanks. Unfortunately I'm in the west of Ireland! But the more help I can get with diagnosing or even describing the problem, the better my chances of finding someone decent over here to look at it, I think.

 

[SimonG]

Post up some photos of the pipecwork. More the merrier

 

[diamondgas]

:iagree: pictures or a line diagram would be helpful ...

 

[nehie]

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.

 

[SimonG]

Is there 4 tappings on the back of the stove? Also are the pipes staggered i.e. top pipe from left and bottom pipe from right. Distance to cylinder will also be an issue.

 

[nehie]

They do seem to be staggered. Not sure about the tappings. I'm attaching two photos here of the pipes at the back, from the left and from the right, if you can seem them through the cobwebs!

 

[diamondgas]

Do you live in bungalow? Where abouts is the pump situated, do you know where the pump thermostat is situated nehie?

 

[nehie]

The pump is close to the cylinder, in the kitchen (so also on the ground floor). There is a thermostat in a room upstairs, above the stove. I'm not sure whether or not there might be second thermostat... unlikely I suppose?

The new part of the house, where the stove is, is a dormer-type effort. The old (very old) part, where the range is and the cylinder, is a bungalow. Sorry I know this is exceedingly complicated! Am so grateful for all your help.

 

[diamondgas]

The pump is close to the cylinder, in the kitchen (so also on the ground floor). There is a thermostat in a room upstairs, above the stove. I'm not sure whether or not there might be second thermostat... unlikely I suppose?

The new part of the house, where the stove is, is a dormer-type effort. The old (very old) part, where the range is and the cylinder, is a bungalow. Sorry I know this is exceedingly complicated! Am so grateful for all your help.

My thoughts so far of the limited personal understanding of the lay out and situation of pump, overheat pump thermostat and pipework, is that circulation is slow, overheat stat is in the wrong place and it sounds .... dare I say it ...... limited in installer knowledge? I am not HETAS but still have some understanding, I hope!

 

[SimonG]

:iagree: Sounds like a bit of a dogs breakfast, really need to see how it's tied into the system. It doesn't sound good or cheap to put right unfortunately.

 

[nehie]

"Limited installer knowledge" is what I've always suspected (or feared). Do you have any suggestions of what I might put to a plumber? (As I said, two of them have failed to identify the problem already.)

I should add that the oil-fired range central heating system worked perfectly for seven years before we added this stove to it in 2007. And it still does – it just doesn't heat enough radiators. If I had had even an inkling that this system wouldn't work before I installed it, I could blame myself.

The oil system (also added in 2007) also works fine, apart from the trickle from the expansion tank that I mentioned before. It's a dual-coil cylinder but as far as I know one of the coils is for the oil burner and the other is shared by the two solid fuel devices.

Sorry for going on AND ON here!

 

[nehie]

My thoughts so far of the limited personal understanding of the lay out and situation of pump, overheat pump thermostat and pipework, is that circulation is slow, overheat stat is in the wrong place and it sounds .... dare I say it ...... limited in installer knowledge? I am not HETAS but still have some understanding, I hope!

Just want to add re the thermostat: the pump can also be turned on manually. I can turn on the pump the minute I light the fire in the stove, and the problem still happens.

 

[nehie]

:iagree: Sounds like a bit of a dogs breakfast, really need to see how it's tied into the system. It doesn't sound good or cheap to put right unfortunately.

I was afeared of that. The piping around the cylinder is concealed behind some wood panelling but, if it would be any help, I might be able to persuade Him Outdoors to take it apart tomorrow so I can photograph it. I don't know if that would help pinpoint the problem but let me know. He won't speak to me for a week if it doesn't!

 

[diamondgas]

Just want to add re the thermostat: the pump can also be turned on manually. I can turn on the pump the minute I light the fire in the stove, and the problem still happens.

If you can turn the pump on and nothing happens regards the radiators heating up then there's something stopping the water from being pumped around. that could be a faulty pump, a manual or electronic valve somewhere that is closed or a serious blockage!! Where is the pump situated? Can you get a picture of that and any pipework around it? It could also be air, that depends on pipework configuration ... ?

 

[Nostrum]

You Need to find out where the expansion/vent pipe tees in, if its in the wrong place because it's been tagged into an existing system, you'll just pump water up the vent. Might also explain why the oil boiler is trickling at the same time.

 

[nehie]

If you can turn the pump on and nothing happens regards the radiators heating up then there's something stopping the water from being pumped around. that could be a faulty pump, a manual or electronic valve somewhere that is closed or a serious blockage!! Where is the pump situated? Can you get a picture of that and any pipework around it? It could also be air, that depends on pipework configuration ... ?

I'll try and post some pictures tomorrow of the piping around the pump - it's behind the panelling. Thanks. Gosh, really hope it's air! That sounds nice and simple

 

[nehie]

You Need to find out where the expansion/vent pipe tees in, if its in the wrong place because it's been tagged into an existing system, you'll just pump water up the vent. Might also explain why the oil boiler is trickling at the same time.

Where would I look for that? Up in the attic?