Y-plan valve causing boiler shutdown when switching positions

fronty · Dec 17, 2018

Hi, I have a Y-plan 3 port valve in my system, no idea of make, it's been installed for a number of years has been working fine, but now I've had a new boiler fitted it seems to be a lot more sensitive to temporary interruptions in flow, e.g. when the valve switches between mid position and heating only, the boiler shuts down for a few minutes before eventually firing again.

I suspect it's because when the valve is turning it momentarily shuts off the flow to both mid and heating ports - my question is would a newer valve solve this (i.e. are modern valves designed not to interrupt flow whilst turning)? Or would a bypass solve this (I don't have one)? Or should I just not worry about it?

ShaunCorbs · Dec 17, 2018

nope thats how 3 ports work best option is switch to an s plan system

Knappers · Dec 17, 2018

The increased off time will be an anti cycling feature of the new boiler. It won't be the flow but a momentary interruption in run signal to boiler.

fronty · Dec 17, 2018

Is this behaviour normal on a Y-plan system?

Would prefer if the boiler stays lit whilst the valve is switching, but doesn't sound like there's a lot I can do about it.