3 cold radiators on top floor

[huwy123]

Hi,

I've a 4 year old townhouse with an ideal classic se15ff boiler. I've noticed now having put the heating on that 3 rads on the top floor are stone cold (as are the pipes to and from the rads). Other radiators on the top floor are working fine.

I also found the pressure was very low. I've now topped this up and bled all radiators but the problem remains. Due to the low pressure I'm assuming that the problem is likely to be due to an airlock in the pipes...??

I've tried switching all radiators off and turning the heating on to try and blast through the airlock - no luck

I'd be grateful for any suggestions on troubleshooting this? Should I drain off and refill the system perhaps? I have little plumbing experience but have some handy friends!

Cheers,

-H

 

[Agile]

Where is the pressure gauge and what is it reading now?

Have you tried turning off all the WORKING rads?

Tony

 

[huwy123]

Hi tony,

Thanks for coming back.

The pressure gauge is located on the top floor by the hot water tank and reads 1.5. It was right down to about 0.2!

I have tried turning off just the working rads - that's what I meant originally sorry.

-H

 

[namsag]

if the offending rads are completley full of air. and you have turned all the others off to try and force heat into them.
Would be looking at thermostat pins stuck on rad valves.

 

[huwy123]

Hi,
The rads aren't full of air. I've bled them and now only cold water comes out. Also the pipes to and from the rads are also stone cold - hence I think there may be a pipe blockage elsewhere. Any suggestions?
-H

 

[namsag]

Do they have thermostatic valves on them

 

[Agile]

If you turn off each rad valve in turn then does plenty of water still bleed out ?

Tony

 

[huwy123]

Hi,
Yes they are all modern rads with therm valves. Tony are you suggested I turn off just the cold rads (or all) and bleed? What is that going to tell me? I can try this later when I'm home.
Thanks again for your help.
H

 

[namsag]

More than likely the pins are stuck down on the trvs . remove the heads and give the pins a gentle tap to try and free them.

 

[huwy123]

thanks namsag. I did look at the pins previously and they seem to pop up and down ok to me (but then I'm not a plumber). Wouldn't the input pipe be hot if it was the TRV?

 

[huwy123]

I've just tried bleeding out half a wash-basin's amount of water from one of the non-working rads. I switched off all the radiators in the house except the one I was bleeding and put the heating on. My thinking was that if there was an airlock then it would bring it out. However it looks like I was wrong as they still don't work!

Could it be a faulty valve? The water pressure was dropping as I drained - I had to keep topping it up. Therefore I assume there is no blockage....?

Can anyone suggest what to do here? I am stuck!

-H

 

[Agile]

Can anyone suggest what to do here? I am stuck!

-H

Perhaps you did not understand what I was trying to get you to do.

Go to each non working rad in turn!

Turn off each rad valve in turn and see if plenty of water still bleeds out REGARDLESS of which rad valve is turned off!

Thern tell us the result!

Tony

 

[namsag]

Huwy not being cheeky .but you prob work in an office and are not mechanically minded, ,
Did you try freeing the valves. just pay some one to have a look

 

[Agile]

90% of the population seems to work in offices and does't do practical things!

When I worked for the BBC, I suppose I spent 80% of my overall time in an office!

It was the other 20% which was the most interesting! 10% of that in the desert in Libya and Qatar!

Tony

 

[spacethegas]

90% of the population seems to work in offices and does't do practical things!

When I worked for the BBC, I suppose I spent 80% of my overall time in an office!

It was the other 20% which was the most interesting! 10% of that in the desert in Libya and Qatar!

Tony