Hi all, I am deperate for some help - my controller for my CH and HW was damaged during some building works. I have bought an identical controller and fitted exactly as it was but it will only turn on the boiler for HW.
If I bypass the controller and connect the HW wire and CH wire to the live - I have both HW and CH fine. But if I connect just the CH to the live I get nothing??
Any help - I am stuck here!!!
Thanks in advance!
snipped-for-privacy@hotmail.com (Carl) wrote in news: snipped-for-privacy@posting.google.com:
Sounds like a problem with the 3 port valve, if that's what you've got.
When the HW cylinder stat calls for heat, the boiler and pump are started, as the 3port valve defaults to leave the HW circuit open but when the room stat calls for heat, the boiler and pump are not started until the valve has actually diverted to open the CH circuit to the rads. It's done by the microswitch that is operated at the end of the valve's travel.
This stops the boiler and pump trying to work into a closed circuit if the valve breaks.
You may also, if it's accessible, be able to change just the valve's electric motor; me, I'd buy a new actuator.
You may be able to remove the electric bit from the valve, check that the valve itself is not seized solid, and replace the motor section, without disturbing anything wet.
If it's an old valve, (like mine was ;-( ) you'll have to replace the whole thing - the good news is that they're pretty well interchangeable.
HTH
mike
It could be. It could also be a gravity fed HW system with the new programmer set to fully pumped not gravity settings.
Adam
That would be my first port of call. I haven't looked at new controllers for
20 years now but my old and still reliable (which must be a first as most of the others weren't) Potterton EP3000 has a switch or moveable cam to be more accurate to switch between the two systems.-- Malc
The system is a pumped system (well I assume so, as the old timer/controller was set to pumped and worked fine) One thing I forgot to mention - when I originally connected the old controller back on. I accidentally put two of the live feeds together with the CH wire, this caused the breaker to trip - but could this of caused damage further up (in the boiler somewhere??) If so- why would the CH work (albeit only with the HW)???
If it is my 3 port valve (how do I know if I have one)?? How do I locate it?? etc etc.
Any help appreciated!
Carl
In message , Carl writes
Was one set to gravity and the other to pumped ?
If you'd mentioned the controller make and model, it might have been possible to give some better advice
Its a hortsmann/newlec h51 channel if this helps
snipped-for-privacy@hotmail.com (Carl) wrote in news: snipped-for-privacy@posting.google.com:
It's between the boiler and the HW cylinder, a T shaped fitting, (3 pipes, 3 ports, geddit)
One pie from the boiler, one to the side of the cylinder, and one goes off to the rads.......
Your accident is not likely to have caused damage, except maybe to the 3 prt valve, which we suspect anyhow, as the pump and boiler still function.
The central heating will work, in one scenario, because the cylinder is calling for heat, and that fires the boiler and pump regardless, and takes the CH with it if the room stat is operating, but if *only* the room stat is calling for heat, the boiler is called indirectly via a microswitch on the 3 port valve, and this is where the failure is.
Some wiring diagrams here;
It's important that you find out if your system is fully pumped, or gravity HW, for the assembled team of experts ;-) to help.
mike
h21 not 51 as originally stated.
My point is that if there was a problem in the boiler - surely it wouldn't work at all (see above)?
It is fully pumped system. I have had a look at the 3 port valve and the manual open switch is just very loose and after taking the cover off, it does not do anything if you move the switch. There is also a paddle position indicator A, B or in the middle (A is cylinder B is Rads) the paddle remains in the middle position.
Can I repair or do anything to the 3port valve? (by the way it is a Landis and Staefa MAV-322)
Any help appreciated.
Carl
snipped-for-privacy@hotmail.com (Carl) wrote in news: snipped-for-privacy@posting.google.com:
I don't know the valve, come to that I only know about 2 types.
You may be able to remove the whole actuator, complete with cables, with a couple of screws, and leave the brass in situ.
If you can do this, operate the valve with pliers to make sure it works.
If so, you may be able to replace the elecrical part (if it's still current!). Check with a plumbers merchant. I don't know how you would test the motor, but you can get one for about a tenner if you're up to replacing it.
If you can't get a new actuator, or you can't separate the actuator from the valve, you will need a new valve, which these days comes in 2 parts, the brass bit and the electric bit.
You will need to drain down the system, at least partially, replace the valve (fortunately they're pretyy interchangeable).
It's not that tough, I had exactly the same prob last year, got the diagnosis from this group, and replaced the valve in a short morning.
mike
Thanks - I will have a crack at it!!!! Carl
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