Our central heating has developed a fault in that the valve is not responding to the room stat. I have changed the synchro motor on it but to no avail. DHW work OK. I can get the heating on by pushing the valve/motor manual lever round until I hear the microswitch make and then leave go. It stays in position until the room stat is made and then the valve closes. once the stat calls for heat again, i need to move the manual lever again.
snipped-for-privacy@mbro.ac.uk wrote in news:1129403647.369135.252050 @g47g2000cwa.googlegroups.com:
Get power off the system at the fuse, the cables of interest are at mains potential!
Check the connections from the wiring centre to the stat are sound.
If they are, possibly the stat has failed; check the connections to the stat; if they seem ok,short the two wires together - there's usually only two active conductors - apply power again and see if the valve operates.
I was more alarmed at your alarming shouts of turn the power off etc... when the lever is on the outside of the valve. Do you turn the power off ewvery time you operate a light switch?
No, I'm assuming that Wayne, who has tried changing the valve motor, is looking for another line of enquiry. I'm suggesting for some reason the room stat may not be calling the valve, even if it's clicking, due to duff contacts or connections, and that they should be checked.
Do *you* leave the power on when you remove or change a lightswitch, specially if, as at the wiring centre, you're liable to be surounded by loads of earthed copper? which was the main reason *I'd* be super careful.
But then I've retired after a working lifetime among lethal voltages, I can only hope your luck holds if that's what you would like.....
Mike, the circuit is calling for heat but the valve is still not moving. What are the internal wiring of the valve switches that are operated by the motor? could it be one of those that is saying it is made when it actually isn't?
snipped-for-privacy@mbro.ac.uk wrote in news:1129662172.983678.241660 @f14g2000cwb.googlegroups.com:
I'm not as expert as some, but let's have a go.
When you say the stat is calling for heat, is a live getting through the thermostat all the way to the valve actuator.
Ypu will need the wiring diagram or actually trace the switched live back frob the stat to be sure of this.
Then, is there a neutral on the other side of the motor; a faulty connection anywhere could cause it.
If all this is true and the motoer has been correctly replaced it *must* go!
The valve must work first, then at the end of it's travel it operates an internal switch that calls the pump, so the first thing you need to fix is your valve motor - it appears from your post that the actual brass bit of the valve is working, and shouldn't be stalling the motor.
If push came to shove, you could wire the motor dirctly to the mains to see if it works.
I'm a bit concerned because you haven't revealed much about yourself, like the level of your experience with this sort of thing, in spite of what Lurch says, exposed mains around lots of earthed water pipes can be BLOODY dangerous if you don't know what you're doing, and even if you do, and get careless. Only you, at the moment, hoe you stand on that.
Probably an easier fix is to replace the whole actuator, these days they come off with 2 screws, and you will get a wiring diagram with it - I hope.
I do this because the microswitches can fail, and if the motor fails the switch may be ready to.
"It stays in position until the room stat is made and then the valve closes. once the stat calls for heat again, i need to move the manual lever again."
I'm not too clear about this bit from your first post, I thought the lever latched and stayed put as an emergency mode.
I'm worried in case you have a "diverter" valve, I have no experience of this type except I know it looks like a normal 3port valve; the normal valve only has one switch that makes the pump work, there is no switch required to actuate the valve, the stat does that.
There are good wiring diagrams available, but I'm b****d if I can find one, I can't even find Honeywell's website, where the classic diagrams live, and it's getting late.
I think you should repost and hope Set Square, Ed Sirett, or one of several others takes it up.
On this newsgroup, this thread is deeply buried by now, and you'll have to try again - there's lot's of help, you were just unlucky first time to draw answers from a grouch and a moron!
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