Worcester boiler condensate won't drain.

[Steve2]

Good afternoon all,

I have a Worcester boiler installed recently. It was moved from the first floor to the loft. Existing 22mm condense pipe was extended to the loft. It looks like the old pipe has no slope and prevents air to get into the boiler condensate trap, preventing condensate to drain. After the pipe is blocked, when the engineer removed the boiler connection, the pipe sucked air and started to drain immediately.

The installer offers me a pump or replacing the old section which would mean a lot of work such as lifting the floorwoods, breaking the tiles etc. My proposal was to install an air admittance valve on the PVC condensate drainage. The pipe will suck air from the AAV and push the water with gravity (almost 3m fall). Please see the sketch drawing of the system. attached.

In theory, it should work, however, have you had any similar issues? Have you got any advice on the issue?

Thank you very much in advance,

 

[Scott_D]

You need to sort the problem area, especially with a aluminium heat exchanger boiler.

 

[Chuck]

Your diagnosis and proposed remedy seem wrong to me. Air should get down into the trap down through the boiler not up from the outlet. You must have a blockage somewhere. Possibly a temporary block installed for the move that was forgotten about.

It a registered 'Gas Safe' engineer to find and fix the problem for you. Don't be tempted to DIY.