Hot rads upstairs cold rads downstairs

[Gonzo1489]

Hi folks! Anyone good at problem solving.

I have a traditional open vented, pumped Y plan heating system. Put cleaner in the system a few weeks ago to stop the kettling coming from the boiler. Drained down a couple of days ago refilled and added inhibitor.

The problem - I have hot radiators upstairs but cold rads downstairs. Me thinks it be an airlock

What I have done-

Checked the pump – spinning like a goodun.

Turned all the lockshield valves upstairs down to just a quarter turn. – didn’t work!

Blead off 10 litres from downstairs outlet.- didn’t work!

Blead 10 litres from the valve of the heated towel rail in first floor bathroom next to cylinder cupboard– didn’t work!


Connected downstairs outlet to mains water and with the rads locked except the one with the outlet open and the bathroom towel rail open – pump 5 bar water up through the system until it reemerged from the F&E overflow. – didn’t work!


Connected mains water to the top of the heated towel rail. Put hose on downstairs outlet and opened it. Put a bung in the F&E tank to block the feed pipe. Pumped mains down through the system. – didn’t work!


Ran all the radiators individually.-Guess what– didn’t work!


Today I removed the pump – clean as a whistle.

What on earth can I try next????

Thanks in advance. The Gonz.

 

[OLLIE20]

Get it nice and hot, then turn all rads off upstairs fully, if you have air in it downstaiirs drops, there will be less resistance throgh the rad valves at quater of a turn,and water will always take easiesr route

 

[Gonzo1489]

Hi Ollie. As they have thermostatic valves on them, do I need to fully close the lockshield as well

 

[OLLIE20]

No, just close all TRV's

 

[Gonzo1489]

Done that. Downstairs rads now up to heat. What next. Wait I guess?

 

[OLLIE20]

Open back up upstairs TRV's and should be job done, might have 2 bleed a few rads, might not

 

[Gonzo1489]

Ollie. If only life was simple. Downstairs rads cooling down since I opened up the top rads. Off to price a job. This heating system is driving me nuts.

 

[kevplumb]

balance the system

see FAQ

 

[Gonzo1489]

All the rads upstairs are only opened a smidge. If I close them any further they wont come on.

 

[gas_man_gaz]

prob a partially blocked cold feed

 

[Gonzo1489]

Gaz. Could you elaborate on that please. How do I deal with that if that is the problem?

 

[Gonzo1489]

Gents. Thanks for all your help. I am not a heating engineer and am at a loss to know what I can do next. I thought the cold feed is from the F&E tank. All the rads are full of water. How is this stopping the rads downstairs getting hot?