3 port valve failure

[bobplum]

The 3 port valve on my heating/hot water system has burnt out, the main boiler CB trips out.

If i disconnect all the electrical connections to the valve will the system be useable by manually switching the valve?

TIA

Bob

 

[cross thread]

no

 

[bobplum]

OK thanks for the reply, is there anyway of making the system work, short of replacing the valve?

 

[cross thread]

valve 30 quid you need one so why not replace it

 

[bobplum]

i would do but it looks like the system needs to be drained to replace it, i can't see anyway of getting the valve off without removing the complete thing, i don't mind messing about with electrics not so confident when it comes to drain and filling systems.

The valve is a very old looking acl lifestyle mid postion valve with no release button.

just wanted to get some heat while i wait for a plumber to turn up next week hopefully

 

[bobplum]

Finally got around to replacing the valve, fitted a drayton mid postion valve, MA1/679-3

All went ok the CH now works fine but i can't the HW to work.

Replced all the wires colour for colour old to new, but when i switch the programme on for HW nothing happens, checked the cyl stat that seems ok.

Pump runs and rads get warm and the room stat works when the programme is on for the CH, but no HW when on on its own or when on with the CH.

any bright ideas?

TIA

 

[cross thread]

have you moved the valve to auto sometimes come in maual position

 

[bobplum]

have you moved the valve to auto sometimes come in maual position

yes, this looks ok, just looking at the wiring diagram supplied with the valve it looks like for some reason HW Off from the programmer is permanently live, this is connected to the grey wire on the vlave and too satisfied on the cyl stat.

So perhaps even through the HW on lamp is coming on on the programmer maybe the programmer got damged when the valve overheated?

Also noticed that if i put the HW on and turn the cyl stat to calling for heat i've got 240v on all 3 of the cyl stat termainls!

 

[jackthom]

Hi you don't say what make programmer you have.

Can you disconnect the HW OFF wire on the terminal strip and measure the voltage coming from the programmer, just in case a fault or error in wiring is providing the constant high voltage from elsewhere in the system.

 

[bobplum]

Hi you don't say what make programmer you have.

Can you disconnect the HW OFF wire on the terminal strip and measure the voltage coming from the programmer, just in case a fault or error in wiring is providing the constant high voltage from elsewhere in the system.

Hi, thanks for this.

I have disconnected HW Off from the terminal strip and then set HW on from the programmer, which is an iflo with seperate controls for hw and ch, the HW off wire is still live, and HW on is dead, so i guess this means there is a problem with the progrmmer?, the green light for the HW does come on.

 

[jackthom]

Does the HW OFF line ever go down to zero volts? I'm asking just in case the two HW leads have been swapped over.

 

[D_Hailsham]

Also noticed that if i put the HW on and turn the cyl stat to calling for heat i've got 240v on all 3 of the cyl stat terminals

That definitely should not be happening. It could be a faulty cylinder stat or feedback from the wiring centre.

Do you have a multimeter?

 

[bobplum]

Does the HW OFF line ever go down to zero volts? I'm asking just in case the two HW leads have been swapped over.

No, it doesn't seem to matter what combination of HW & CH i have set it's always live

HW off is a yellow wire on the terminal strip and HW on red.

I have taken the programmer off of it's base plate and according to the drawing on the back of it the cables are correctly connected, ie Yellow to HW off and red to HW on.

Also on the back of the programmer are 3 jumpers these are set to

I, 7 and P, no idea what these are.

 

[bobplum]

Also noticed that if i put the HW on and turn the cyl stat to calling for heat i've got 240v on all 3 of the cyl stat terminals

That definitely should not be happening. It could be a faulty cylinder stat or feedback from the wiring centre.

Do you have a multimeter?

Removed the stat and checked it seems to be OK, yes I do have a multimeter.

As is said in my last post to jackthom, it seems to me, however im no expert, that the root cause is that HW off from the programmer is permantly live.

 

[jackthom]

With the removed wire restored at the terminal strip, I'd be inclined to use some short wire links at the programmer baseplate to take the place of the programmer and check out the rest of the system.

eg start with a link from Live to HW ON which should give hot water only.