This is a bit long, sorry....

An acquaintance has a heating problem. For complicated reasons, I'm in charge of sorting it out, at least for the next few days.

It's a y-plan system with an Ideal Mexico Super 3 boiler. The boiler is at least generating heat. It's been messed about with by a large contractor X, and for safety it seems one should assume they've broken everything they've touched. In particular, I know they replaced the ballcock on the heating header a few weeks back, and replaced some rotten overflow pipe (but not all of it!). I also know that they recently replaced the 3-way valve, and power flushed the system. They are now recommending that the landlord strip out the existing boiler/cylinder and replace with a combi. For £6K. I told you they were a large contractor....

It's leaking warm water from a pipe outside the building. All indications point to this being the heading header tank overflow.

The cylinder stat is not actually measuring the temperature of anything except a random piece of air. I've attempted to duct-tape it to the cylinder, though I don't expect that to last long. The tenant has been using the immersion heater, so the water is rather hot!

I orginally thought that the leak was due to overheating, but after I discovered that X had replaced the ballvalve, it seem more likely that they hadn't set it properly. I had a look at it the previous night, but was in a rather precarious position standing on dodgy carpentry...

Apart from the leak, the real problem is that the radiators are not getting hot (except the first one on the circuit). I'm not that familiar with 3-way valves - I presume that it's a mid-position valve rather than diverter (it was recently replaced by X) but I don't know.

When I arrived, the first rad was cold. I turned off the HW, and left CH on continuous, and the first rad warmed up - but no others. I presume that this indicates at least some flow, but possibly minimal. I don't *think* it is heating up just on conductance through the pipes.

I have searched in vain for any bypass which might have been fully opened (and in any case I'd then expect the return to be hot, and if I'm correctly identifying it, it isn't).. All I can think of is an airlock. I bled all upstairs rads and got nothing but water. I verified that the pump valves were open. Lots of heat seems to be going up the pipe to the header tank, which again (I think) suggests mimimal flow on the rad circuit.

It seems to me that I ought to go back and ensure the ball valve is set properly, and probably replace the cylinder stat. That, however, is secondary to the heating problem, and while those two things will stop fresh water entering the system, they won't fix any existing blockage.

The only possibility I can think of is to whack the pump up to max and close the first rad, and see what happens. Any other suggestions welcome! Obviously there is the possibility that the valve isn't opening properly, though I'm not clear how I can test that.

I've got a plumber who ought to be competent coming round on Sunday (I hope), but if I can get them -and their young kids - some heat earlier, we would all be happier.

On Fri, 02 Dec 2016 09:06:38 -0800, bblaukopf wrote:

The only possibility I can think of is to whack the pump up to max and
close the first rad, and see what happens. Any other suggestions
welcome! Obviously there is the possibility that the valve isn't opening
properly, though I'm not clear how I can test that.

I've got a plumber who ought to be competent coming round on Sunday (I
hope), but if I can get them -and their young kids - some heat earlier,
we would all be happier.

Don't do anything, you are clearly don't have a clue how it works, wait
until the plumber comes.
Turning up the pump to maximum will probably cause more over-run into the
header tank, so any water bubbling there will be a hazard, as well as
probably being the cause of the hot over-flow.

On Friday, 2 December 2016 17:06:42 UTC, wrote:
This is a bit long, sorry....

An acquaintance has a heating problem. For complicated reasons, I'm in charge of sorting it out, at least for the next few days.

It's a y-plan system with an Ideal Mexico Super 3 boiler. The boiler is at least generating heat. It's been messed about with by a large contractor X, and for safety it seems one should assume they've broken everything they've touched. In particular, I know they replaced the ballcock on the heating header a few weeks back, and replaced some rotten overflow pipe (but not all of it!). I also know that they recently replaced the 3-way valve, and power flushed the system. They are now recommending that the landlord strip out the existing boiler/cylinder and replace with a combi. For £6K. I told you they were a large contractor....

It's leaking warm water from a pipe outside the building. All indications point to this being the heading header tank overflow.

The cylinder stat is not actually measuring the temperature of anything except a random piece of air. I've attempted to duct-tape it to the cylinder, though I don't expect that to last long. The tenant has been using the immersion heater, so the water is rather hot!

I orginally thought that the leak was due to overheating, but after I discovered that X had replaced the ballvalve, it seem more likely that they hadn't set it properly. I had a look at it the previous night, but was in a rather precarious position standing on dodgy carpentry...

Apart from the leak, the real problem is that the radiators are not getting hot (except the first one on the circuit). I'm not that familiar with 3-way valves - I presume that it's a mid-position valve rather than diverter (it was recently replaced by X) but I don't know.

When I arrived, the first rad was cold. I turned off the HW, and left CH on continuous, and the first rad warmed up - but no others. I presume that this indicates at least some flow, but possibly minimal. I don't *think* it is heating up just on conductance through the pipes.

I have searched in vain for any bypass which might have been fully opened (and in any case I'd then expect the return to be hot, and if I'm correctly identifying it, it isn't).. All I can think of is an airlock. I bled all upstairs rads and got nothing but water. I verified that the pump valves were open. Lots of heat seems to be going up the pipe to the header tank, which again (I think) suggests mimimal flow on the rad circuit.

It seems to me that I ought to go back and ensure the ball valve is set properly, and probably replace the cylinder stat. That, however, is secondary to the heating problem, and while those two things will stop fresh water entering the system, they won't fix any existing blockage.

The only possibility I can think of is to whack the pump up to max and close the first rad, and see what happens. Any other suggestions welcome! Obviously there is the possibility that the valve isn't opening properly, though I'm not clear how I can test that.

I've got a plumber who ought to be competent coming round on Sunday (I hope), but if I can get them -and their young kids - some heat earlier, we would all be happier.

You don't have circulation. Could be bad pump, bad 3 way valve or less likely a blockage. I don't think we can tell you which.


NT

On Friday, 2 December 2016 19:54:14 UTC, Alan wrote:
On Fri, 02 Dec 2016 09:06:38 -0800, bblaukopf wrote:

The only possibility I can think of is to whack the pump up to max and
close the first rad, and see what happens. Any other suggestions
welcome! Obviously there is the possibility that the valve isn't opening
properly, though I'm not clear how I can test that.

I've got a plumber who ought to be competent coming round on Sunday (I
hope), but if I can get them -and their young kids - some heat earlier,
we would all be happier.

Don't do anything, you are clearly don't have a clue how it works, wait

A bit harsh, given I come here to learn, and have learned quite a bit over the years. The point of closing the first rad was to see if it was just heating up by conductance, without any circulation at all. If so, then closing it would not reduce its temperature at all, but otherwise rad 2 would heat up a bit. I agree that speeding up the pump is probably clutching at straws. I was very very tired on Friday.

If it were my system, I'd be stripping things down - but it's not, so I get none of the cost saving and all of the potential downsides out of DIYing it.... I have no desire to do the work, but I do want to understand it.

Turning up the pump to maximum will probably cause more over-run into the
header tank, so any water bubbling there will be a hazard, as well as
probably being the cause of the hot over-flow.

The header is as still as a mill pond up there, I had a look at it.

Anyway, plumber says he's coming round tomorrow. Hope he shows...

On Friday, 2 December 2016 17:06:42 UTC, wrote:
This is a bit long, sorry....

An acquaintance has a heating problem. For complicated reasons, I'm in charge of sorting it out, at least for the next few days.

It's a y-plan system with an Ideal Mexico Super 3 boiler. The boiler is at least generating heat. It's been messed about with by a large contractor X, and for safety it seems one should assume they've broken everything they've touched. In particular, I know they replaced the ballcock on the heating header a few weeks back, and replaced some rotten overflow pipe (but not all of it!). I also know that they recently replaced the 3-way valve, and power flushed the system. They are now recommending that the landlord strip out the existing boiler/cylinder and replace with a combi. For £6K. I told you they were a large contractor....

It's leaking warm water from a pipe outside the building. All indications point to this being the heading header tank overflow.

The cylinder stat is not actually measuring the temperature of anything except a random piece of air. I've attempted to duct-tape it to the cylinder, though I don't expect that to last long. The tenant has been using the immersion heater, so the water is rather hot!

I orginally thought that the leak was due to overheating, but after I discovered that X had replaced the ballvalve, it seem more likely that they hadn't set it properly. I had a look at it the previous night, but was in a rather precarious position standing on dodgy carpentry...

Apart from the leak, the real problem is that the radiators are not getting hot (except the first one on the circuit). I'm not that familiar with 3-way valves - I presume that it's a mid-position valve rather than diverter (it was recently replaced by X) but I don't know.

When I arrived, the first rad was cold. I turned off the HW, and left CH on continuous, and the first rad warmed up - but no others. I presume that this indicates at least some flow, but possibly minimal. I don't *think* it is heating up just on conductance through the pipes.

I have searched in vain for any bypass which might have been fully opened (and in any case I'd then expect the return to be hot, and if I'm correctly identifying it, it isn't).. All I can think of is an airlock. I bled all upstairs rads and got nothing but water. I verified that the pump valves were open. Lots of heat seems to be going up the pipe to the header tank, which again (I think) suggests mimimal flow on the rad circuit.

It seems to me that I ought to go back and ensure the ball valve is set properly, and probably replace the cylinder stat. That, however, is secondary to the heating problem, and while those two things will stop fresh water entering the system, they won't fix any existing blockage.

The only possibility I can think of is to whack the pump up to max and close the first rad, and see what happens. Any other suggestions welcome! Obviously there is the possibility that the valve isn't opening properly, though I'm not clear how I can test that.

I've got a plumber who ought to be competent coming round on Sunday (I hope), but if I can get them -and their young kids - some heat earlier, we would all be happier.

If there's water coming out of the overflow, switch off the circulation pump & see if it stops.
This indicates bad design of the system.
Often happens when a boiler has been changed.
Sometimes turning down the pump speed cures it but then the CH doesn't function properly.
Sometimes it's cured by converting the system to a pressurised one.

If the overflow still runs, it indicates a leak on the domestic hot water heat exchanger.

On Sunday, 4 December 2016 09:36:49 UTC, harry wrote:
On Friday, 2 December 2016 17:06:42 UTC, wrote:
rflow, switch off the circulation pump & see if it stops.
This indicates bad design of the system.
Often happens when a boiler has been changed.
Sometimes turning down the pump speed cures it but then the CH doesn't function properly.
Sometimes it's cured by converting the system to a pressurised one.

If the overflow still runs, it indicates a leak on the domestic hot water heat exchanger.

The plumber did show on Sunday, and diagnosed it as just that a leak in the coil.