Honeywell 2 way valve short circuited by dripping flange

[mtl]

I have been searching for a "how to replace a motorised valve head" article on the web or an exploded diagram of a Honeywell valve and cannot find either one.

Description of problem:
The 3A fuse in the plug controlling the CH junction box (pump, boiler, motorised valves and HW tank thermostat) in my house tripped recently. Fault identified by electrician as a weeping flange from pump (after heating had been off for 1 week), which had dripped onto a Honeywell 2 way motorised valve and shorted it. The electrician cut through the lead (containing 5 cables) to provide a temporary solution in order to restore CH, but not HW (now using immersion heater).

My question is this. I read that the valve head can be replaced withouut draining the system. Do I just replace the motor (blue and black wires)? How can I test the motor? The orange and grey wires disappear into the back of the plate where the motor is mounted. If I need to replace other parts will I need to drain the system and which screws should I remove ( I have already removed the 2 screws which secure the motor, but it is unclear what each of the other screws is four (there are about 4 more) .Which part is most likely to have shorted, the motor or the element powered by the orange and grey wires?

Any help would be appreciated.

BTW, the flange on the pump no longer seems to be weeping. I guess it had something to do with the heating being off for a few days. When I repair it, have you any tips for stopping it happening again. Would self amalgamating tape around the valve housing to completely seal it be advisable

 

[croydoncorgi]

First off - it's (obviously) bad practice to position an electric valve where it can get dripped on! At this point, moving it is probably the last thing on your mind but you should do SOMETHING to keep water off it. Unfortunately, no zone valves are waterproof (or even drip-proof). Sealing it up completely is probably not an option - it would possibly overheat. Better to put something waterproof on or above its top surface to deflect any water elsewhere, away from the electric bits.

Second point is that the most water-prone thing in the valve is NOT the motor. It's the microswitch that connects the grey wire with the orange wire. (You didn't say but it sounds most likely you've got a 2-port valve, not a 3-port.)

Third point: once the valve has dried out internally, it MIGHT have come to no serious harm. Before doing anything else, test for high resistance to casing and the earth wire from the all the other wires, for about 2 - 3Kohms brown to blue (the motor) and open circuit between grey and orange. If all those check out, the head may be OK. Maybe worth reconnecting the wires and (carefully) test it with a new fuse of the right value.

If you do decide to replace the head, check whether the silver cover off the valve has a raised round bump on the top. If it has, the head is replaceable complete without draining the system. There are TWO (only) captive screws which attach the actuator to the valve body. Undo those and lift off the actuator. No bump means it's a (really!) old valve which does NOT have a replaceable head. theoretically, you can get an upgrade kit but you'd have to drain the system anyway to fit it so you might as well replace the whole thing.

To fit the new actuator, my recommended technique (after turning power OFF!) is to cut the wires from the old actuator back to about 20mm long on the junction box terminals, so you can see from the remaining coloured stumps where they belong, then undo the terminal screws one at a time to remove the stump and insert the relevant wire from the new actuator. Last step is to engage the lever at the end of the actuator in its latch and fit the actuator onto the valve body, re-tightening the 2 screws, then replace the cover. When you power everything back on, the first thing you'll hear from the actuator will be a click, as the latch automatically disengages, which usually indicates that you got it right and it's working!

 

[ChrisR]

small things -
the bit about the bump is only true if its a Honeywell head.
If the head IS removable it's pretty clear which screws you undo so there's a doubt...

if it IS a 2 port valve, loosening the 2 compression nuts slightly will possibly allow you to twist the whole valve so the head is out of the drip zone!

 

[mtl]

Thank you Croydoncorgi for talking me through it in fine detail. Thanks too to ChrisR. Not sure I believe ChrissR is really in Antarctica, but no doubt a bit of central heating knowledge is handy down there! Thanks for the tip about repositioning the valve. I will look at that.

First off I have asked [email protected] to post a picture I have forwarded to them showing the valve with the motor removed. If you cannot see it yet, please check back some time soon. It will hopefully help you identify whether the valve head is replacable or not. There is no bump on the top of the housing, so it may be that it IS an old valve.

It is a 2 port valve. The label inside the cover/housing does not contain an obvious model number as such. It just says "Motorised valve", has a little diagram for flow direction and some figures concerning diff. pressure, static pressure and fuid temp and the information"Honeywell, Toronto Ontario Made in Canada" then the number40000593-073.

As there has been no further dripping in the vicinity of the valve in the past two weeks since the incident occurred, and it is warm in the airing cupboard, my bet is that everything is now dry. It seems from your response that my best course of action is actually to check the resistance as you suggest, then switch off power and rewire up the valve to the junction box to see if the component that was shorting has dried out, without further damage, and the whole unit will work again. I can do this easily as the electrician cut the cable close to the junction box (much as you had suggested) so I can match the wires to the correct terminals on the junction box). I may not get around to it for a couple of days, but will repost when I have done so.

 

[DIYnot]

Here is MTL's Picture.

 

[mtl]

I have been using immersion heater for hot water for past 2 months as too busy to try and fix. Th picture is now posted. If anyone out there can advise as to the type of valve I have and whether I can change it without draining the system I would be grateful for the help.

 

[ollski]

the model number will be on the bottom of that valve on the outside as you look at it. To replace it you need an adaptor plate and replacement head. Drain down and undo the 4 brass screws, fit the new adaptor plate with 2 screws with concave threaded heads then pop the new actuator and and screw with other 2 screws. 2 port number is v4043, make sure adaptor plate is same number.

 

[Soggy_weetabix]

are you electified to do this? Moan Moan. Sorry I was tony for a minute!


Did you lot know a new heat ex on a baxi galaxy retails at 112 notes plus the vat?

Cheap as the bugie so to speak.

Sorry, hijacked thread. Just was amazed

David