3 wire 2 port valve problems.

[SPC]

Ive been to a range unvented cylinder tonight and the hot water is getting too hot, 70 deg C and its the two port valve at fault which is a 3 wire Range 2PV.

My question is, can i replace it with the lovely 5 wire honeywell 2PV i have at home and just wire the live neutral and earth same as the other 3 wire or do i need a 3 wire 2PV specifically? :6:

 

[SimonG]

Five wire will do without using orange and grey.

 

[SPC]

i assumed so, just wanted some reassurance before fitting it at custards. cheers bud

 

[SimonG]

I would imagine the 5 wire would be more expensive but I don't know what the difference would be.

 

[villa_tom]

I didn't know you could do that! Thanks, you learn something new everyday

 

[SimonG]

It's basically the same beast, but your just not using the microswitch. I wouldn't have given it much thought but I used a 5 for a 3 because for some reason I had a 3 on the van and it was about 40 mins from home and didn't fancy going back.

 

[Puddle]

it maybe this valve does not control the temperature of the hot water,if only live with no orange and gray wires,maybe just wired into the high limit thermostat thus closing when hot water over heated,there may be another valve that operates from the normal cylinder thermostat,this will have the boiler control micro switch,use to do this originally,now over heat linked to stop boiler,only trouble with this is it stops heating side too

imho

 

[buckley plumb]

if you ever come accross the old three port valve 3 wire spring return you can use the 5 wire mid position valve and just join the grey and white wires and it will work as the 3 wire diverter.blue to neutral white and grey joined to sw live .

ant

 

[SPC]

Thanks for your input puddle, room for thought there. I know on this occasion its the valve at fault as when the programmer is calling for central heating only the CH is working and the HW coil is also red hot. unless something is way way wrong somewhere, i shall be finding out on saturday 🙂

 

[SPC]

as it turns out, it was a 4 wire!! wiring was a bit of a mishmash and couldnt see the fourth wire at a quick glimpse but straight forward swap as the honeywell just had the extra earth. cheers for the input lads

 

[stevetheplumber]

How can a three wire valve switch the boiler on ?

 

[SPC]

one would assume the room stat or cylinderstat would do the switching of the boiler on / off and make the valve live simultaneously to open? ive just known of 3 wire valves before and thought i had this situation

 

[buckley plumb]

when ever i change zone valves now i always take a chocolate block connector and a surface pattress and cover . if the wiring centre is a mess and there is the chance of disturbing wires etc i cut the existing zone valve wires and connect the new to that in the new surface box.

ant

 

[SimonG]

when ever i change zone valves now i always take a chocolate block connector and a surface pattress and cover . if the wiring centre is a mess and there is the chance of disturbing wires etc i cut the existing zone valve wires and connect the new to that in the new surface box.

ant

Same thing here, 6 way junction box, helps when the wiring centre was screwed to the wall before the cylinder was installed and you need to be a black belt at yoga to get into the wiring centre.