Cold rads upstairs

[hoffstarr]

Hi

I recently had the heat exchange and pcb replaced when the central heating boiler started leaking. The heating seemed to be working fine, but I went away for a few days and on my return I have found that only the downstairs rads are working, and one upstairs that seems to get it's feed directly from the pump. I am guessing it has something to do in the loft but I have absolutely no idea what I am doing or looking for. Any ideas?

 

[IanPlumber]

Hi,
I will ask a few simple questions first.
1, Have you bled the rads upstairs for air?
2, are all the rads upstairs cold or are there just cold spots on the rads?
3, What boiler do you have (combi or a standard type)?
4, Do you have TRV's or standard rad valve?
Why to you think that it has something to do in the loft?
The upstairs rad that is working would happen to be the bathroom rad by any chance would it?

 

[hoffstarr]

Thanks for your reply.

I have bled them all, no air just clear water.
The cold rads are completely cold, pipes cold too.
It is a standard boiler.
They are standard valves I think.
The rad upstairs that is working is on the landing, bathroom rad not working. I think it's something in the loft because the rads that aren't working have pipes going up to the loft - these pipes are also cold.

 

[IanPlumber]

Hi,
It could possible be your pump has failed. If you know where it is, Check that it's running. It may have a lever on the side (depending on what pump it is) with some speed settings, try moving it to a faster setting.
It could be an air lock that has found its way to the top of your pipework in the loft. You may have an air valve in the loft pipework, Check the pipework at the highest point (should look like either a brass upstand with a flat screw bit on the top or a plastic bottle with a red cap). Unscrew the cap SLOWLY and you may get air out of it.
You can back fill your heating system but i would recommend getting someone in who knows what their doing as this can backfire.
Also try shutting off all of your downstairs rads and see if the heat gets to the rads upstairs, if it does your system may just need balancing.
It's unusual that your landing rad is on and not your bathroom one as this is the one normally taken off the feed to your cylinder. But not know how the pipework is run it sounds more plausible that you have either an airlock or your pump has failed.
Hope this helps.

 

[hoffstarr]

Thanks very much.

I have tried changing the speed of the pump and it makes a noise like it is going faster! I'll have a look in the loft and see if I can find an air valve.

Thanks again!

 

[IanPlumber]

Hi,
Before you check in the loft, Shut all of the rads that are getting hot and it may be enough for the pump to dislodge the air lock.
Good luck.
P.S. Do you know if you have separate zone valves for upstairs and downstairs or do you have a 3 post valve. Check in your cylinder cupboard. A 3 port valve is a valve in a "T" shape with a small wired box on the top. There should be A,B and AB ports stamped on the side.
If you don't have one of these you will probably have 2 single zone valves. If this is the case try opening the one feeding upstairs manually (small lever on the side).

 

[hoffstarr]

Ok there was some air in the pipes so I let that out, but there is no change. I have tried closing the working rads but still nothing. I have a 3 port valve.
So have I tried everything?! Is it time to get a professional in? (again!!!)

 

[IanPlumber]

Hi,
Without me actually being at your house theres no a lot else i can do.
Looks like you will have to call out mr plumber.

 

[Bahco]

Try reading post 8 in the FAQs first.

Might save you some cash