Honeywell 3 port mid position valve - problems with...

[Jerry.]

Anyone know of any issues with Honeywell 3 port mid position valves, i.e. installation, location or in service problems etc., I've had three or four go faulty in the last 4 years since the system (and I hasten to add) was professionally installed and it sounds like I might be approaching another !

It's either been problems with the valve it's self or the motor drive not operating (opening the required port(s)) and thus causing the boiler to overheat and cut out due to there being no flow - and causing hot water and steam to be forced up into the boiler feed / expansion tank :~(

[Lurch]

I've never come across a problem with them, at least not the way you say, they'll normally go on for years. It sounds as if it's not been installed correctly. Check the honywell site for your valve and have a look at the technical specs and data sheet.

SJW A.C.S. Ltd.

[Peter]

[Jerry.]

[ re subject line ]

Well it was installed in a loft, on the east aspect and the problems this time started after a couple of (relatively) deep overnight frosts.... Hummm !

One more question, would one expect a symphonic flow if there was a complete pump failure but the ports on the above valve had opened IYSWIM ?

[Lurch]

Is that making music with water? ..

SJW A.C.S. Ltd.

[Lurch]

With the proper frost protection? ..

SJW A.C.S. Ltd.

[Jerry.]

Not sure what you mean by that, but if you mean making steam, hammer blow type sounds, and forcing water up into the feed / expansion tank, YES :~(

One pipe form the boiler is VERY hot (can't touch it for more than a second or two) and the other is not more than warm. This morning there was not heat in any radiator and the HW hasn't been re heated....

[Jerry.]

Well it doesn't seem to have any type of frost stat if that is what you mean.

Even more Ho Hummms...

[Lurch]

Sorry, obviously not everyone has my sense of humour, look at 'symphonic flow'. ..

SJW A.C.S. Ltd.

[Lurch]

I think it would be recommended to fit a frost protection kit to the components in the loft. Assuming the boiler is in the loft also you want a wall mounted frost stat by the boiler and a pipe stat on the return, connected in series across the permanent live feed and the trigger wire on the valve, usually the brown. ..

SJW A.C.S. Ltd.

[Jerry.]

Oh right, I was a bit short on humour this morning....

[Phil Nettleton]

this last part dosnt make sense as the valve will never shut both ports no flow will be caused by a pump failure if the valve is not powered the hw port is open if it is the ch port will open or a blockage in the system phil n

[Set Square]

I agree entirely. Unlike using two 2-port valves - which can both be closed at the same time - the 3-port valve doesn't have a position which shuts off all the flow, and is unlikely to be the cause of your current problems. The water always has somewhere to go unless all your radiators have TRVs on them and they are all shut. If this *is* the case, you need to make some design changes to the system!

It is far more likely that your lack of flow is due to problems with the pump. How is this wired - is it simply wired in parallel with the boiler or is it connected to the boiler's pump-over-run connection?

[Jerry.]

Yes the pump is connected via a pump-over-run connection. It's looking like a defective sensor on the boiler, there is no electrical feed to pump.

I starting to suspect this / might / have been the (intermittent) fault since the boiler was first installed and not the three position valve.......

Thanks to all for the replies.

[Set Square]

You *have* got a permanent live feed to the boiler in addition to the switched live, haven't you? Without this, the pump won't over-run - but it will still run when the switched live (coming from the programmer and/or room stat) is on.