Discuss Problem with central heating flow after pipe alteration in the Plumbing Jobs | The Job-board area at PlumbersForums.net

When we moved into our house we had the old conventional boiler moved from the kitchen to the loft and changed to a combi.

Recently we've had a kitchen refit, and part of this was moving the old boiler pipes up into the ceiling space. Since this we have experienced no end of heating circulation problems!

I've drained the whole system and refilled, which worked for a few days perfectly then the whole of downstairs stopped working, upstairs radiators work perfectly still! I drained again and refilled..... same again!

The pipes that was moved up into the ceiling space were the flow and return from the old conventional boiler, so had a slight drop on them, now in the ceiling space they have no drop and just a loop. So could this be the cause of an airlock?

Any help much appreciated.... the Mrs thinks moving these pipes has nothing to do with it, yet it's been working fine for over a year
 
Doubt it's anything to do with the actual moving of the pipes but more likely an airlock as a result of draining down and refilling. Run your heating and then turn off one side of every radiator that's working, this should force the air lock out. Try that first and report back.
 
Thanks for the replies. I will try isolating the working radiators.

See the phot I've attached. This is how the pipes used to be. Dropping from the ceiling to the old boiler. Since we've had combi installed they just linked them together within the cupboard.

With The kitchen refit they raised them up into the ceiling still linked together. Since this.... the problems begin which leads me to believe this is where the airlock could be!?

20190122_224738.jpg
 
shouldnt of linked them together bet its short circulating
 
its not going to the rads just going round in a loop, water will always take the easiest path

must of provided that bit of resistance to stop it short circ
 
What would happen if we were to have this pipe section split and both ends capped off?

it will work

whats the problem its giving you no heat to the rads and boilers not running for a long time?
 
to prove its not air turn all the rads off the turn the boiler on if theres any air it will move it around if you hear any air open one rad back up and the air should collect in there
 
you could just cut the link and put in a 22mm isolating valve. turn it off and see what happens. if it works leave it closed. if the loop is part of the rad circuit you just turn it back on. saves having to do the job twice
 
Disagree here, I've had numerous installs where the primary flow and return have needed to be linked.

My interpretation of what the OP wrote is that the previous boiler had an indirect DHW loop and and a CH loop. The new boiler was a combi so the DHW loop became redundant so it's been decommissioned and left sealed and cold.

It's possible that the redundant pipework was repurposed in the new system but it doesn't seem likely and nothing the OP has said suggests to me that this is the case. I think it's probably a red-herring.
 
My interpretation of what the OP wrote is that the previous boiler had an indirect DHW loop and and a CH loop. The new boiler was a combi so the DHW loop became redundant so it's been decommissioned and left sealed and cold.

It's possible that the redundant pipework was repurposed in the new system but it doesn't seem likely and nothing the OP has said suggests to me that this is the case.
They was linked previously and the system worked, so they must be purposely linked. All that's changed is the pipes have now been linked in the ceiling instead of dropping into the unit.
 
They was linked previously and the system worked, so they must be purposely linked. All that's changed is the pipes have now been linked in the ceiling instead of dropping into the unit.

Either way, I can't envisage them being the root cause of the problem unless they were both part of the radiator circuit and an inverted-U was created by the process of moving them. Neither seem likely to me.
 
Last edited:
Turn off all the upstairs radiators completely and see what happens downstairs ......... could be a simple case of balancing ......
 

Reply to Problem with central heating flow after pipe alteration in the Plumbing Jobs | The Job-board area at PlumbersForums.net

Creating content since 2001. Untold Media.
Back
Top