Central Heating 3 way valve

alleycat`

I have a question for central heating minded people.

Background:-

Our central heating system uses a siemens (landis/staefa) 3 way valve (MAV-322C) to switch back and forth (or midpoint) between hot water and the central heating system.

Whilst the valve body itself is fine the motor housing (syncron motor) tend to die over time and need replacing.

I've never been able to locate by itself an equivalent Syncron motor and the only other option is to purchase the full "motor housing" ( part RMH).

The RMH is becoming increasingly difficult to source and progressively more expensive when all i really need is the syncron motor.

It's apparent looking at the syncron motor this unit uses a longer "brass drive cog" (don't know the correct term).

This means that ones i can easily source wouldn't fit suitably to open/close the valve as the drive cog wouldn't reach / engage.

So to my questions:-

Does anyone know where i can source a syncron motor that fits this particular model (with this extended drive cog).

If not, is it possible to remove the "drive cog" from a failed unit and migrate it to another unit?

cheers,
-
Richard

Gloomendoom

Why not change the whole valve to something more reliable or easy to get parts for?

alleycat`

Gloomendoom wrote: »

Why not change the whole valve to something more reliable or easy to get parts for?

The "cupboard" the valve is located in makes it somewhat of a sod job to take it out.

Replacing the pump a few years ago was an adventure in swearing and contortion.

To be honest replacing a synchron motor would be a 15 minute piece of work with the way the unit "head" is designed.

The valve body is reliable it's just the fact they have chosen this none standard "cog" length that is the issue.

If i have to re-do the entire thing i will but re-doing all the wiring and having to drain the system down / for the sake of what should be a £10 - £15 part is a tad annoying

Hence i thought it worth an ask

*j*

Is it this motor?

http://www.toolstation.com/shop/p68222?table=no

alleycat`

*j* wrote: »

Is it this motor?

http://www.toolstation.com/shop/p68222?table=no

It's that type of motor but the "drive cog" on that one, the ones at the usual DIY places, and the danfos ones are all shorter.

It's ridiculous that a consumable part is modified to be "special" in this way.

If the drive cog can be removed it will fit that type but I've no idea if that's possible.

macman

It's known as a 3-port valve. A diverter valve is what you have inside a combi to switch the flow from CH to DHW.

alleycat`

macman wrote: »

It's known as a 3-port valve. A diverter valve is what you have inside a combi to switch the flow from CH to DHW.

Fair point.

I did put it was a 3 way valve in the original "body" of my post but the subject was misleading. I've corrected it.

alleycat`

After a bit of asking around I've managed to find out the synchron is referenced as part RM240.

Isn't a huge amount cheaper than buying the full RMH part and is a lot more expensive that the equivalent models for other manufacturers.

Think i'm going to go the route of replacing the lot in the summer as suggested previously and just put up with the swearing and contortion.

xyz123

To state the obvious but have you tried to contact the manufacturer or a specialist plumbing shop..