Fitted a open vent boiler with a 3 port valve, spark wired it. I noticed when both demands are on and the HW is switched off the boiler cuts out, pump overun then relights. Should it cut out, I thought it would stay lit and the valve would just move
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Yeah honeywell with a Vaillant 428. Cuts out, temp goes down a bit then it fires back up
Yep they all do that.
Reply to the thread, titled "3 port valve" which is posted in UK Plumbers Forums on Plumbers Forums.
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