Mitsubishi Ecodan 8.5KW one zone gone offline and missing from main controller

[quality]

I don't agree with damaging the heat pump if a zone valve doesn't respond quick enough to allow full flow. I do agree with full flow being required so as to allow correct output form the heat pump. If there is a buffer installed it doesnt matter what type of zone valve is used so long as it works.

 

[Brambles]

Generally, it is a time delay either 50 seconds after the power is supplied to the valve or 20 seconds after the micro switch closes. A decent valve should be fully open within 12 seconds

We do a 12kw High Temperature Heat Pump that will deliver flow at 65 degrees C - that has to operate through a buffer.

If you look at the warranty conditions of most reputable heat pumps valve arrangements and buffer sizing is covered in some detail.

 

[SJB060685]

Thanks Brambles. A time delay was one way I was picturing it done

 

[petehuws]

Hi Gents,
Solved the missing zone 1 UF heating, had a bit of time this morning & the problem was away from the heat pump. A failed shut Danfoss HPA2 actuator valve ahead of the remote pump in my attic. Both the pump and valve are energised by a shared relay which closes when the call to heat comes along, powering the pump & energising the Valve to open. I've manually opened the valve & have flow through to the pump and now to the floor. Should of really suspected the weakest part first.
As they say though "The fix is always the last thing one tries"..
Merry Christmas all.

 

[SJB060685]

Merry Christmas to you. Glad you've found the culprits

 

[petehuws]

Merry Christmas to you. Glad you've found the culprits

Thank you very much - you were the trailblazer that set me on the path... All the very best
Pete

 

[SJB060685]

No worries my friend, although I set you on your path Brambles superior knowledge taught me a couple things I didn't know, so thank you to both of you.