No hot water after replacing port valve head

[dribbles3]

Hi,

Last night I replaced our faulty Honeywell 3 way port valve head - it hadn't worked since we moved in three years ago - it wasn't letting flow into the hot water cylinder - just into the central heating. It never bothered us as we have electric shower and dishwasher - no real need for HW.

I finally put a new (well used, but working) one in last night and wired it all up exactly as the old one had been. Seemed to all be working OK. CH worked fine. HW worked fine. Only problem was that I couldn't get HW without CH. I guessed that this was possibly a result of it being wired up wrong. No bid deal though - I boxed up the wires and thought I'd worry about it again in spring when I wanted to turn the CH off.

I woke up this morning to find the CH on but the radiators cold. The boiler was on, the pump was running and the water was flowing around, but all the pipes were cold.

I checked the boiler and things seemed OK - pilot light on. I tried changing the temperature, cranking up all the thermostats, tried various combinations of HW on/off; CH on/off, but no mater what, all the pipes coming out of the boiler stayed cold (though flowing).

Is it possible that I did something wrong when installing the new port valve head/motor that would cause the boiler to stop working, or is it probably just a coincidence that the boiler broke down the morning after?

Thanks in advance

 

[dcawkwell]

Sounds like there is no circulation going on otherwise the heat would be getting away from the boiler.

 

[dribbles3]

Hi - thanks for reply.

I think the water is circulating round - the pump is working away and I can feel the water moving through the pipes - the boiler isn't getting warm either though so it seems that perhaps the boiler just isn't firing up?

 

[Phill Peck]

Where did u get a "used but working" head from and how do u know it works

 

[dcawkwell]

Hi - thanks for reply.

I think the water is circulating round - the pump is working away and I can feel the water moving through the pipes - the boiler isn't getting warm either though so it seems that perhaps the boiler just isn't firing up?

Boiler isn't firing. The boiler fires when it receives a live switch from the 3 port valve. But this usually switches the pump on as well.

Check the orange wire from the 3 port valve is at 240volts.

 

[dribbles3]

Hi checked the orange wire on the 3 port valve as suggested. In doing so I notice that the neutral wire from the boiler had come lose. Reattached and bingo - boiler firing again!

So many wires and in an awkward position in a dark cupboard...

Still no joy on getting the port valve into position 3 (ie HW with no CH) but as gasservice1985 has identified... that is likely a result of my used head - which a friend had spare (been lying in his loft for a good few years though).

At least I've got CH and HW back working now - I'll get another head and re-examine the wiring in the spring - in the meantime thanks for all your help - saved me lots of grief from the family!

 

[MANDATE]

Two points I'd like to make!
Getting HW on it's own, needs the valve to be in the HW only position.
The HW only position is the rest position, the valve returning there by a return spring when HW only is selected. So is it not returning? gears fouling? motor energised when it should not be so?
Second point, the boiler receives power ONLY from the valves orange wire when in the CH only mode.
For HW only or HW with CH power comes from programmers HW ON wire and goes through cylinder stat.

Because there are two supplies of power, they are joined at the terminal holding the orange wire, so be aware the orange will show 'live' regardless of the power source