- 16 Dec 2009
- Reaction score
my combi boiler biasi m90e 24s the hot water works fine central heating not working it is turned on and up to pressure is it the pump or pcb or something else please help
so does the diverter valve have its own motor could it be a blockage in the valve its selfwont be the pump , as this runs for both H.W & C.H , doubt if it is the pcb its mostlikely to be the divertor valve , e.g the motor , which is what you would check first .
it is on and there is no room stat all rads have trvsCheck the timeclock is on and the room stat is turned up.
ok found it i think it is working but maybe it is not doing what it should i am thinking of tacking valve apart and cleaning it would this be a good ideayes the divertor valve has its own motor .
ok i bridged across the two terminals and the motor seemed to turn i have not taken it off yet so dont know if it is doing what it should do or if pcb is telling it to work how do i test it is workingif the divertor valve motor is faulty , than it needs replacing , there are 3 wires going to it are'nt there ? & the terminals are marked 1 2 & 3 , 1 is
CH live terminal 2 is neutral & 3 is H.W live terminal , the motor will always rest in the H.W position , for C.H a spindle inside the valve will be seen to move forward , push out the head of the motor , it can be viewed , this in turn forces a spindle down inside the actuall divertor valve when C,H is demanded , in H.W the spindle (pin) will withdram into the motor
in operation e.g C.H demand ther would be 230 V across terminals ,
1 & 2 , in H.W 230V across terminals 3 & 2
divertor valve , it is held in place by a push on type circlip , pull it & this will release the motor , in the end u will see a brass spindle ,( dont disco' the 3 wires) with the boiler off, or in the H.W mode , the spindle will be retracted inside the motor , if it does not look like it is push it with a match or similar & it will fall back into the motor . turn on the C.H u should feel the motor vibrate , & the spindle should move forward the, boiler is now in the C.H mode , u should have 230 v across terminal ,1 & 2 , the motor is supplied by the control p.c.b , the spindle in the motor pushes down on a siindle within the brass housing if u put your finger in the top u will feel it & u should be able to push the spindle down , by pushing it down u have in effect put the divertor valve in the C,H mode., the valve should take approx 6 secs to motor
over into the C,H mode .hope this makes sense ??
i know how to get it off ,there are no numbers on the terminals so from left to right brown ,blue,black, if i connect brown to black i can hear it brown to blue nothing black to blue nothing ,i also found out if i take the senser plug off and replace it it fires up for a short time so i am still not sure that it is that motor ,any more ideas thanks so far ps i found spindle and pushed it down with ch on nothing happend
thank you got a new diverter valve motor ch working fine now thanks again and best wishes to you and yoursYou need to set the boiler into CH mode and look at the diverter valve motor.
The motor actuator should be "out" so the brass is flush with the plastic surround.
If its not then the boiler may not be in the CH mode.
Have you checked the thermostat( if fitted ) ? There should be "0" volts across the connections when its in the "on" setting.
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