3 way Diverter power problem!!!!! HELP

[phil 0904]

Fully pumped Y system

Hi Guys
The problem I have has been ongoing for several years. Diverter valve been changed twice. All works fine on HW only, when switching to CH, diverts & works fine. When changing programmer back to HW only or turning down thermostat the diverter does not switch back to HW. I have been controlling it manually by the switch on the diverter or turning cyl stat down & then up again (hence HW taking priority) I have renewed the cyl & room stat so know there's no problems there. I have checked & re-checked the wiring & its is all OK (plus it was all working correctly before this problem started). Now I am retired & have more time, I want to sort it out properly. I'm sure its some sort of wiring issue, something not commanding it to divert. Or is it the boiler, timer of pump overide. I haven't got a multimeter & not really that confident in using one. My system has no connection from controller to term 7 so cannot have CH on only. I did copy the following statement from another forum for testing valve

Turn main switch OFF
Turn CH OFF at programmer
Turn HW OFF at programmer
Set cylinder stat to minimum
1. Turn main Switch ON: Check grey wire - should be live.....NO
2. Turn HW ON: Check grey wire - should be live....YES
3. Turn HW stat to Max: Check grey wire - should not be live...YES
4. Turn HW OFF: Check grey wire - should be live...NO


On my test, grey wire only live when HW on, so YES to only numbers 3 & 4.
Sorry to all in advance for such a long story, but was tring to give as much info as possible
Regards Phil

 

[plumben]

Has Just the Head of the valve been swapped in the past or the Hole valve?

 

[phil 0904]

Plumben, thanks for the quick response...No the head & body both changed twice, system was flushed & cleared both times.

 

[jonnyswamp]

Look at a wiring guide again and check if it's correct
I assume you have a mid position valve and not a diverter

 

[phil 0904]

Hi jonnyswamp, Yes checked several times, wiring def correct, valve is fitted correct way round. Mid position / Siemens 3 way valve

 

[jonnyswamp]

What make was the original mid pos valve and did this always work

 

[phil 0904]

All siemens valves, I wanted to swap like for like. Which is why I never got the Honeywell, thought that would be less aggro

 

[Old Account]

Hello phil,

If you do not feel confident enough using a multimeter then get a qualified engineer in so he most likely solve your issue which you currently have.

If zone valves are charged twice I assume that the wiring it's a little messy ... It's highly unlikely that you have got 2 new zones fitted and both are wrong.

 

[jonnyswamp]

If 3 port, cyl stat and room stat are all new and it's wired correctly, it can only be programmer
Esp if changing 3 port didn't solved it last time

 

[phil 0904]

Thanks for the replies guys. I think as the programmer is fairly old (Landis & Gyr RWB 200) I will replace, any suggestions for a decent direct replacement. Then if all that fails will get a qualified engineer in to sort it out

 

[jonnyswamp]

Pretty much any twin channel will do, but when you fit it, remove all the wiring from 10 way box and start again using the honeywell wiring guide
Which is easily found on google
good luck