Switchmaster Blue VA1 3 port switch replacement

[victormeldrew]

I have the Switchmaster Blues!

My VA1 is leaking, and the back plate is beyond repair this time - its badly corroded. The system is drained, I have just replaced the gate valves either side of the pump as they were leaking as well, and I have a radiator to replace (the original reason for disturbing the system - the wife damaged the microbore when moving furniture and it leaked into and damaged the garage ceiling).

OK, I am prepared to replace the VA1, but I've read some posts saying this needs piping changes, but some say just wiring changes. Which is it? If its wiring AND piping, what piping changes are needed?

Any help gratefully received!

(PS I had I posted this onto an old thread, but I thought a new thread might get noticed quicker!)

 

[avidfan]

Pipework may require minor alteration. Wiring is as follows: (if you are fitting a Honeywell, first colour is the S/master)
Blue to Blue, Earth to Earth, Orange to Orange, Yellow to White, White to Grey, Red to be linked with Orange.

 

[victormeldrew]

Pipework may require minor alteration. Wiring is as follows: (if you are fitting a Honeywell, first colour is the S/master)
Blue to Blue, Earth to Earth, Orange to Orange, Yellow to White, White to Grey, Red to be linked with Orange.

Thanks Avidfan. I have searched, and have a few references to the wiring changes, but one more won't hurt Its the "Pipework may require minor alteration" bit I need clarifying. Is that simply because the valve itself is a different size, or to do with the fact that the VA1 has the head on the side rather than the top? Or is it more fundemental like the H/W expects the boiler feed in a different place?

 

[Soggy_weetabix]

if you have a system with all switchmaster compenets you may need a link in the wiring centre if you change vlv.

Never normally needed though but sometimes those 6 wires dont work on a five wire h/well.

Same the old honeywell vlvs with a relay on the side which are 6 wires.

David

 

[avidfan]

The two outlet ports on the Honeywell will be marked 'A' and 'B' (I think B is hot water) check with the instructions. depending on the orientation of the s/master you may have to alter the pipework to make sure that the Honeywell is upright or no further over than 90 degrees. This is so that if the valve body leaks, water does not end up in the electrics of the head.
I'm sure that the nuts on the s/master don't fit the H/well, so you'll have to cut the olives off.
Good luck.

 

[Soggy_weetabix]

No they wont!

Many a day with junior hack saw wresting those valves out!

Dave

 

[victormeldrew]

Thanks fellas. Fortunately there is plenty of access, and the 3 port is right at the front of the airing cupboard at chest height!

I've cursed the piping over the years for being a mess and in your face when you open the airing cupboard, but right now I'm blessing the plumber who put it in. There's just one of the nuts about an inch off a joint, otherwise there is plenty of pipe with enough give even if I do have to cut off the olives. And loads of access!

Honeywell is on its way, so if it arrived tomorrow I should get the job done. New rad is fitted, with nice chrome 15mm piping straight down through the floor - I hate microbore, and I'd rather risk a leak in a 8mm to 15mm adapter than leave the stuff visible.

So far so good.

 

[victormeldrew]

The new valve arrived, no problems at all with fitment. The old VA1 came off no bother, the olives twisted off cleanly using a pipe wrench, and the Honeywell slotted in its place no bother. Instructions with the Honeywell were pretty clear. All the pipes were fine, the head now sits on top of the valve where the VA1 was on the front face of the T.

I was expecting a nightmare, but it went on like a dream, and everything is working fine.

 

[corgiman]

nice one mate well chuffed for you

aint nothing like a job you have been dreading going like clockwork

 

[ollski]

Yep, glad it was easy...these jobs tend to get a bad name because its a ball ache having to do a wet job when you know in your head it should be a nice 5 min dry one.

 

[Coety]

found this reply and wired in a new wiring center with the old switchmaster, and still can't get fully independant control of DHW and CH.
DHW on its own is OK, as is request for both (until cylinder stat is satisfied and then the boiler stops!).
Request for CH on its own does nothing.
Am I missing a trick here? (apparently the valve worked OK before the client fitted the new wiring center! I'm just trying to pick up the pieces......)