Radiators hot even with central heating off.

[molibdimum]

Here goes...................
I had an extension built about one year ago and decided to have my boiler replaced with a Worcester Greenstar HE and resituated as we needed two new radiators fitted in the extension.
Since then I have had some hot radiators even when the central heating is turned off.
The plumber has revisited three times but all he has done is turned the pump speed down from 3 to 1 and tell me not to worry as I am getting free heat..........the guy obviously thinks everybody is as thick as him.
The only other changes to the system I have had are a thermostat on the hot water tank and a three way valve fitted.
I have tested the three way valve and it is working correctly so how can hot water be getting into my radiators when I dont even have tham on?

 

[Bahco]

If plumbed correctly, the only way hot water can get to your ch side is via the 3 way valve. When your heating is off the valve should shut so that only your DHW will get hot water.
Suggest you look at the valve again, may not be shutting off properly.

 

[scatmanjohn]

Hi...if the valve is working correctly then the plumber could well have connected the pipework incorrectly. Its possible you have reverse circulation.
I'd get back the plumber who did it cos it ain't right.

free heat my a#*e

 

[chrishutt]

how can hot water be getting into my radiators when I don't even have them on?

Installer has probably connected the HW return to the CH return pipes in more than one location (all CH returns should be joined together before connecting to HW return).

This fault would allow circulation of hot water from the HW return pipe to the return from a radiator, then from that rad via flow pipe to another rad, then by that second rad's return pipe to the second connection on the HW return pipe.

If your installer is responsible for this, I would have doubts about his competence. Perhaps you should get someone else in to sort it out.

 

[molibdimum]

If plumbed correctly, the only way hot water can get to your ch side is via the 3 way valve. When your heating is off the valve should shut so that only your DHW will get hot water.
Suggest you look at the valve again, may not be shutting off properly.

I let the whole system go cold and then turned on the HW only.......this resulted in one outlet from the 3 way valve to heat up instantly but the other was initially cold..............this eventually got hot without turning on the CH so I think the HW is coming back through the CH system thus heating the Rads.
I tend to agree with the posts below and I think the plumber has piped up incorrectly somewhere.
My fear is that the problem is now behind my newly fitted downstairs shower where the old boiler was situated.

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Can anyone suggest a reputable national CH specialist that I can get in touch with regarding this problem?

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[oilman]

Tell your plumber (in writing) if he doesn't fix it, you will get someone else to do it, and you will sue him for the money. (You might not but he might just sort it out)

 

[molibdimum]

Tell your plumber (in writing) if he doesn't fix it, you will get someone else to do it, and you will sue him for the money. (You might not but he might just sort it out)

Its not quite as straight forward as that as I employed a builder to undertake all the work so the plumber was employed by the builder.
The money isnt really a problem because I held back £500 from the final payment.
I have lost faith in this plumber so I think the best option is to find another...........hopefully someone who knows what he is doing.