Motorised C/H valve gone wrong.....

Just a long shot....

Switchmaster (Smiths?) VA1 threeport 22mm motorised valve failed.... internettything makes for disappointing outcome.... the electric motor goes, driving the dial round so far, but then sticks and clicks (worn/broken teeth inside (sealed) gearbox?) ..... around 20 years old, obsolete .... c/h feeds in at bottom from pump, out left to hw tank, out right to rads .... gland nuts on pipes are female (threads on "T" of valve are male)...... any ideas, please, folks? Best solution would be if anyone had a gash "blue box" actuator kicking around, as the water valve half is OK!! - it's the actuator that's failed.... it clips on to faceplate with three spring clips, + electrical connections...

Reply to
Ian
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Sounds very similar to my problem. Because I can't afford to rip the CH to bits to replace it, and because mine has a blue cover apparently held on by screws to get inside which I'd have to drill a hole through the partition wall from the stairs, I've been turning mine manually for 2 or 3 years with a 2p piece in the groove in the dial!

Convenient it most definitely is not, but it is survivable, and if you really don't want to rip your CH to bits in such cold weather, the following will get you through the days until you can get it repaired.

It's best to be systematic. Have > Just a long shot....

Reply to
Java Jive

Fixed it.... and, it seems, other people have a similar problem......

Much delving on Internet revealed that Switchmaster VA1 is very very obsolete - as dead as a Dodi, in fact.

Just under £70 for a new valve from Center (one of the Wolseley plumbing companies) - the one you want is EHE0200157 Mid Position Motorised Valve. Phone 0870 8506538

It's not QUITE the same as the original - wire colours are different, there's 5 wires instead of 6, and there is a small difference in pipe length which may need addressing.

Plumbing side: ===========

Switch system off Hook up float in C/H header tank Drain system Undo gland nuts on Switchmaster and remove (I had a problem as I could not move the first pipe out far enough to clear, as it was near the plaster and breeze wall, solved by removing the 3/4" or so of plaster and a shallow bit of breeze.... doesn't show as it's inside airing cupboard...) Clean up pipes after removing old compression gland rings

The pipes on the EHE0200157 do not go as far in to it as they do on the old valve: so I shortened all three of them by around 3/16" each. You MIGHT get away with not doing the horizontal ones, but you will have to shorten the vertical feed one anyway, otherwise the horizontal ones won't even align.

Fit the new valve, RIGHT WAY ROUND..... radiator cct goes to port A, port B towards the HW cylinder; letters are embossed on the valve. (feed at the bottom, you can't really get THAT wrong).

Tighten glands.

Put lever on valve to MANUAL. (I had to use a mirror to see which position was which, you might like to mark the *top* of the plastic casing with a permanent marker, "M" and "A"!!!!!)

You can now refill and bleed the system (I put a can of antileak and a can of inhibitor into the header tank first.)

Unhook lever on valve so it goes to AUTOMATIC.

Now the fun and games.

Wire Colours: ===========

There were two problems that I could see - one, six connections previously, to only five on the new valve; and two: was CH Live from clock for ON on valve, or did live close the valve? (and the same for the H/W?). Using a multimeter indicated that the CH was LIVE ON, DEAD OFF; and the HW was DEAD ON with LIVE OFF.

Seemed to match up with the EHE0200157 description on the installation instructions.

Switchmaster BLUE is equivalent to EHE0200157 BLUE. (Neutral)

Switchmaster GREEN/YELLOW is equivalent to EHE0200157 GREEN/YELLOW (Earth)

Switchmaster WHITE is equivalent to EHE0200157 GREY (HW OFF - 240v live from clock when hot water is off, dead when hot water is required ON) Luckily the Switchmaster and the new valves are the same in this "reversed logic" feed.

Switchmaster YELLOW is equivalent to EHE0200157 WHITE (CH ON - 240 v from clock, dead for OFF. Operates the other way round from the HW part.... !)

Switchmaster RED is equivalent to EHE0200157 ORANGE ( live feed to boiler and pump)

That leaves the wire which was previously connected to the Switchmaster ORANGE..... that connected to the H/W Tank Stat, needs to be live, when H/W is on, so I connected it to the Live feed to boiler and pump.

Wrap up all notes and drawings in a plastic bag and stuff them down the side of the pipework so I (or someone else!!!) can see what was done 15 years previously when the problem rears its ugly head again.

It works, took me about three hours (a professional would have done it in an hour.... :o).... but cost rather more!!!)

Reply to
Ian

When did this become a boiler/CH forum then?!!

Reply to
AJH

When I had to do it myself at home to fix it. :o)

Reply to
Ian

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