Heating Off Rads getting warm

[DEMPSEY1965]

Morning, I have done the above, water on/heating off and bled the rads, no air is coming out. Some of the rads are slightly warm though still. The hall rad, one of the lounge rads. This is driving me insane! Think I will let things settle down and hopefully as time passes and air is the problem it will slowly go away and the rads will not heat up. Incidentally, there is a small red round metal thingy in the airing cupboard on the pipe above the pump but not bleed screw on it.

 

[Harvest Fields]

What valve did the engineer fit?

 

[DEMPSEY1965]

Like for like Drayton

 

[Harvest Fields]

Could be a faulty body but that does not happen often

 

[SavageW]

When you say the whole valve was changed, do you mean just the brass body/water side of your 3port valve or was the actuator changed also? If they have both been changed I would look more down the lines of reverse circulation possibly? Didn't the engineer who replaced the valve test it on hot water alone for a period of time to double check that it was not passing down the heating? Best to probably call the engineer back to double check.

 

[Harvest Fields]

When you say the whole valve was changed, do you mean just the brass body/water side of your 3port valve or was the actuator changed also? If they have both been changed I would look more down the lines of reverse circulation possibly? Didn't the engineer who replaced the valve test it on hot water alone for a period of time to double check that it was not passing down the heating? Best to probably call the engineer back to double check.

That is what you have paid him for!

 

[dan_the_plumber]

Maybe if you have a bypass valve installed that is faulty or not set correctly.
Sometimes plumbers just use a gate valve which pretty much does the same thing.
If you adjust them by screwing them down tighter you will limit the flow yonyhe heating and send it around the hot water coil instead

 

[DEMPSEY1965]

Hi,
Very interesting, regarding the plumber he is competent in plumbing but admits he is not a heating engineeer, my fault but the valve is good so at least I have a new one all for £60 labour 2 hours work. The pipe from the valve that goes to the heating is a touch warm whereas the others are hot! I like your idea of the bypass valve and will try that as I know there is one there pointed out by my plumber. I do thank you for sharing your ideas and knowledge.

 

[SavageW]

Hi,
Very interesting, regarding the plumber he is competent in plumbing but admits he is not a heating engineeer, my fault but the valve is good so at least I have a new one all for £60 labour 2 hours work. The pipe from the valve that goes to the heating is a touch warm whereas the others are hot! I like your idea of the bypass valve and will try that as I know there is one there pointed out by my plumber. I do thank you for sharing your ideas and knowledge.

When you say a touch warm how long has the hot water been on for? If the central heating pipe from the 3port valve is a touch warm an your radiators are hotter then ain't going to be the 3port valve passing. Depends really where the by-pass is piped into on the primary return. I'd honestly suggest looking for a local GSR heating engineer to take a look.

 

[DEMPSEY1965]

Water on for about 5 minutes I felt the heating pipe and at the valve is warmish and the other 2 are very hot, where the pipe goes into the floor it is cold. Thought it may be just heat from the valve/other pipes. The rads are off now so not sure if they are getting hot, think I might just bite the bullet and get a proper heating man.

 

[SavageW]

Water on for about 5 minutes I felt the heating pipe and at the valve is warmish and the other 2 are very hot, where the pipe goes into the floor it is cold. Thought it may be just heat from the valve/other pipes. The rads are off now so not sure if they are getting hot, think I might just bite the bullet and get a proper heating man.

Turn on all your rads again, an just put your hot water on. On your three port valve your going to have the primary flow from the boiler which will be hot, the second pipe (which you say is hot should be to the cylinder coil) the third pipe may have some heat to it but that could be considered conduction along the pipe work. If the pipe you say goes to the floor is cold an I'm assuming that's the central heating from the 3port then I'd say that's just some heat conduction from the valve. Looking at all the responses an help we have tried giving you here it's probably just easyier to get someone who knows what there doing, it will only save you time an money hopefully.

 

[DEMPSEY1965]

Yes, the plumber said it was probably heat transfer and the pipes are exactly how you said. It's not like like it's leaking etc and I have turned all the rads off so not a problem with the heat in summer, just kind of annoying. Thank you all again for your time.