Non Combi boiler - low pressure?

Alex1983

Ah I see, yes now the blockage is clear the chemical will do its work and the flush should stop it happening again.

BG fixed price quote doesn't look so bad now, they would of cleared the blockage, flushed it and gave you a life time guarantee.

Lgas

You also would have gotten a lifetime warranty on the BG powerflush. They could combine the open vent and cold feed to prevent this from re-occurring.