Motorised valve repeated failure

[Corazones]

Hello members,

After frequent tripping of the heating side of the main electrical distribution box, our builder's heating engineer found that the Polypipe 22mm 2-port motorised valve PB9700ZV, after less than three years in use, had developed an intermittent fault to earth. He commented that, in his experience, this item did often had a limited life.

The item was replaced by another identical in May 2017 which immediately cured the problem - but for only seven months, when the frequent electrical fault returned. The problem has been identified and isolated by turning off all underfloor 'stats, which has so far stopped it. We fortunately also have a radiator circuit as well as this underfloor-heated extension; the boiler and its main circulating pump continue to work normally and cause no faults.

Has anyone else had experience of such a problem? If so, can you suggest another (possibly more reliable) brand which would be suitable as a direct replacement?

Any advice would be greatly appreciated,
Alec.

 

[leakydave]

Honeywell Valves for me

 

[oilboffin]

Either honeywell or you could try a danfoss.Bob

 

[stem]

My mum's bungalow has a working 2 port Honeywell motorised valve that was installed when it was built in 1981 from the days before they had inbuilt microswitches, and relays were used for the switching. At least there isn't a microswitch to fail.

Also, I have three Honeywell 2 port valves (with microswitches) that must all be well over 10 years old. They replaced some awful flimsy, plasticy, leaky things.

 

[Wildcat1961]

My mum's bungalow has a working 2 port Honeywell motorised valve that was installed when it was built in 1981 from the days before they had inbuilt microswitches, and relays were used for the switching.

Must of been old stock as I was fitting Honeywell spring return MV’s in the late 70’s.

 

[stem]

Tis spring return, just no microswitch fitted.

 

[whirls]

I am also having problems with repeated failures of PB9700ZV valves. I am on my 3rd one of a 3 year old system. Can I ask Corazones which Honeywell model you used as a direct replacement? and was it possible just to swap over the valve head without re-plumbing?

 

[muggles]

No, you can't just swap the heads, you need to swap the entire valve.

 

[dilalio]

Honeywell - don’t like any others.