I have a Worcester LPG boiler feeding a coil in the water cylinder. I turned it off in the summer and used the immersion heater instead. However, the flow and return sealed system pipework between the boiler and the hot water cylinder has continued to circulate very hot water through the system which is wasted heat (and energy). There are no isolation valves in the flow and return pipework and I don’t really want to open up the boiler to isolate it. Is there a simple way that I can stop wasting energy?
Boiler isolation valves
- Thread starter Diwali
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How do you think you turned it off? If it was still firing and circulating hot water then it couldn't have been turned off. Turn the boiler off at the fused switch.
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Sorry. I didn’t make it clear. I switched the power off at the switch and the db. There is no pump running and the boiler is not firing.
However, both the flow and return pipes at the boiler are very hot as they are all the way to the hot water cylinder a run of approx. 10 metres. The horizontal sections are lagged but not the vertical ones (yet). Without isolation valves in the system I don’t know how to stop the flow of hot water and the resulting waste of heat and energy.
However, both the flow and return pipes at the boiler are very hot as they are all the way to the hot water cylinder a run of approx. 10 metres. The horizontal sections are lagged but not the vertical ones (yet). Without isolation valves in the system I don’t know how to stop the flow of hot water and the resulting waste of heat and energy.
They must be getting hot from somewhere. Can you provide more info/photos of setup? Do you have any solar panels installed? Post a photo of the boiler, evidence of switches being off, and the hot water cylinder please.
Sounds like gravity circulation is taking place.
Thanks for the replies. There are no solar panels. It’s a basic set up with the system boiler heating, through a coil, a hot water cylinder/thermal store. During summer I’m not using the boiler only the immersion heater for DHW. However, the hot water continues to circulate to the point that the boiler casing is warm - presumably acting as a radiator!
Convection does seem to be the culprit. Would draining the boiler circuit while it is shut down be advisable?
Convection does seem to be the culprit. Would draining the boiler circuit while it is shut down be advisable?
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Presumably it's a fully-pumped system, but it sounds like you don't have a 3-port (or two 2-port) valve for CH and HW. If you did, and they're working properly, you wouldn't have the problem. You could fit one, and update the controls, to improve the system. Or just close an iso valve as others have said, but don't forget to open it before firing up the boiler again!
Need more information to make educated suggestion rather then take shot in the dark
1. Circulation taking place between cylinder and boiler while boiler power is off
Question here is, with MCB in off position, the hoiler is depowered, but are the controls also depowered
2. Have been involved in installations where boiler is dead but pump still runs as controls are powered from another circuit.
3. I would be looking for a pump and take it from there. Instead of boiler heating the water in the cylinder, looks like cylinder is trying to heat the boiler as pump is running all the time.
4. Is the boiler above ( higher) than the cylinder? 10m distance suggests mechanical circulation rather than gravity. More so if bulk of the pipe run is horizontal.
5. Service valves under the boiler- disturb this at your peril as most regulars here will tell you. Not unknown for these to start leaking/ weeping when these are operated. Why makers cannot make valves that are fit for the purpose, One make comes to mind where the spindle in the valve snaps When the valve is disturbed.
Can be done but be aware if the pump is causing the circulation as isolation will stress the pump.
1. Circulation taking place between cylinder and boiler while boiler power is off
Question here is, with MCB in off position, the hoiler is depowered, but are the controls also depowered
2. Have been involved in installations where boiler is dead but pump still runs as controls are powered from another circuit.
3. I would be looking for a pump and take it from there. Instead of boiler heating the water in the cylinder, looks like cylinder is trying to heat the boiler as pump is running all the time.
4. Is the boiler above ( higher) than the cylinder? 10m distance suggests mechanical circulation rather than gravity. More so if bulk of the pipe run is horizontal.
5. Service valves under the boiler- disturb this at your peril as most regulars here will tell you. Not unknown for these to start leaking/ weeping when these are operated. Why makers cannot make valves that are fit for the purpose, One make comes to mind where the spindle in the valve snaps When the valve is disturbed.
Can be done but be aware if the pump is causing the circulation as isolation will stress the pump.
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Read what I wrote again please.
Boiler does not need to run to make those pipes Hot.
Pump need not be inside the boiler if boiler Is a heat only boiler
Have known controls to be supplied off ring mains and boiler on own supply for this scenario to take place. Have resolved similar situation before
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