Replacement Three Way Valve - Including Pipe Fittings

[davehart]

Hello folks.

I need a replacement 3 port valve for my central heating system. The current unit I have is a Siemans / Landis & Staefa RHM mid port 3 way valve.

This one: heatingsparescentre.co.uk/siemens-c25/motorised-valves-actuators-c3028/siemens-rmh-2-3-port-spring-return-actuator-p22514

I replaced just the motor housing some time ago but the unit on the pipework is damaged this time around so I need to replace the whole lot. Looking around the valve I have is not that common and pretty hard to get hold of in one complete unit so I'm looking for a replacement.

Which one would be suitable and be a direct swop out for the one I have?

The pipework is 22mm so I need one with those fittings. There are not many plubers around who are free or I trust so I can do the work myself as its an easy job, I just need to make sure I'm getting the right replacement part thats going to fit.

Any help much appriciated.

 

[SimonG]

Trust issues eh! Bit of a bugger that.

Not that easy either, especially if you don't know which valve to use. Not that easy this plumbing lark.

Go for Drayton or Honeywell. Ignore Danfoss imho.

 

[Riley]

Agreed. Assume you're gonna drain down?

 

[Chalked]

Honeywell , but im not trustworthy!

 

[davehart]

Yeah going to fully drain the system down so its safe to remove the current pipework and cut off the power so I can wire the new unit in.

Do most three way valves share the same wiring regardless of brand?

 

[Riley]

There are some which will catch you out. Really depends what you've got now and how it's been wired

 

[PlumbBobBob]

yes most share the same coloured wiring. a good tip is after you turn the electric off, cut the wires at the end where they are wired in leaving the wires in place so that when you rewire do it one at a time colour for colour.

 

[davehart]

5 wire connection for most common types looking around at a few?

 

[Riley]

There are occasional sixes but few and far between

 

[SimonG]

There are occasional sixes but few and far between

Danfoss HSA3CD. Special on camray 5's.

I never wire back into the wiring center. I cut the cable at the head, strip back and use wago's and a wago junction box.

 

[Dotty]

Free plumbers?

What do you do for a living yourself?

 

[joni os]

Yeah going to fully drain the system down so its safe to remove the current pipework and cut off the power so I can wire the new unit in.

Do most three way valves share the same wiring regardless of brand?

Sunvic have 4 wires: white, grey, orange, blue. Only drain sufficient to lower water below valve. Bleed pump on refill. Port A, central heating. Port B, DHW. Get multimeter so you can fault find and assume nothing until it's tested.