programmer

[philsno1]

Last winter my siemans programmer stopped working, I bought a replacement RWB9.cw and wired up exactly as instructions and everything worked fine until summer (but as my heating was always on, no suprise as hot water came on with heating).

With the arrival of summer and no requirement for heating, I turned my heating off and used the hot water only mode, but to may amazement, the heating came on and the hot water also kicked in. I couldn't turn on the hot water without the central heating.

Upon investigation, and after consultation with a plumber friend of mine (who said it would more than likely be my motorised control valve). I bought and fitted a new sunvic 3 port motorised valve.

Now when switching on hot water, only the heating kicks in, the water doesn't get hot.

I would be grateful for anyone's advice on this.

 

[GeckoGas-com]

Does the hot water come on if you switch on the heating?

If so; you've probably fitted the valve the wrong way round

 

[philsno1]

I can't switch on the heating without the hot water also automatically coming on. I suspected that it may be the wrong way around, but I did fit the valve the same way as the previous valve, also the heating pump kicks in when the water is switched on.

 

[GeckoGas-com]

So, yes... The hot water comes on if you switch on the heating, correct?





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To confirm the valve orientation:


There should be an "A" and "B" on the valve outlets....

The "A" should go to the pipe which goes to the radiators and the "B" should go to the pipe which connects into the cylinder.

 

[philsno1]

it appears that the B goes to the cylinder - what do you think would happen if I turned the valve around?

 

[Dan Robinson]

 

[gas4you]

Does this new programmer have to be set for gravity or fully pumped with some dip switches on the back?

Take it off and have a look. Sounds like it is set for a gravity system.

 

[philsno1]

it's got dip switches on the back and the last dip switch is for gravity/fully pumped.
I've double checked the position of these and they are all ok according to instruction leaflet.
As soon as I swithc hot water in on position pump kicks in and central heating is fired up.
I believe the system is a pumped central heating and gravity hot water.

 

[Dan Robinson]

Not with a diverter valve it's not.

 

[philsno1]

Thanks Dan, I'll double check that then, I always thought when it was installed that it was gravity hot water.

 

[gas4you]

Needs setting to fully pumped then.

 

[philsno1]

now set to fully pumped - but still with only hot water switched on, it's the central heating that comes on (without hot water).

 

[GeckoGas-com]

What Sunvic 3 Port did you use?

 

[gas4you]

Wired up wrong or 3 port valve wrong way round or incorrectly wired.

 

[philsno1]

What Sunvic 3 Port did you use?

new valve sunvic SDMV2304

old valve was towerMP3 - 22C

I wired exactly as old valve and fitted valve with ports A & B in same position, also wired RWB9.cw as instructions.