I was wondering if i could get a bit of advice, I've got a Main 30 elite combi and it's not switch over to the central heating from the hot water and after reading a few threads on here i came to the conclusion that it could be the diverter valve so decided to get a repair kit off ebay..... I isolated the water/electrics and drained the combi and removed the valve which did look knackered and replaced with the new one. Repressurised etc but i've still got the same fault. I can push the pin down manually on the diverter valve which then supplies hot water to the radiators so was wondering if it could be the motor that sits on top and is there anyway of testing. Thanks in advance Jonny
Can you unclip the motor and look at it's armature/pin/thingy and see if it comes out when you call for heat?
Yeah Devils Advocate... I've watched the pin on the actuator motor and there is no movement and the led on the front of the combi also does not switch from the hot water led to radiator led. When the fault first developed i could bump the combi into radiator mode by quickly switching the hot water on and off at the kitchen tap and it would eventually switch to radiators but that no longer works, this was the main reason i thought it could be the diverter valve sticking. Thanks
Possibly the motor has gone, but more likely a control problem. You'll need to fault find to check that the controls are telling the boiler to go to heat mode. Means getting inside with a meter, 240v etc so up to you.
Thanks Glad its Friday... I did run a volt meter over the motor connections to see there was a voltage which there was but other than that ive not tested further. I will google for a schematic. Thanks
What if you give the motor a good clunk with a screwdriver handle as it tries to activate...? If it then moves, you can be pretty sure it's a stuck motor. But, as GiF says, the control board - or some associated part - can also be responsible.
Have you demand from the room stat? Could be hall sensor or flow switch stuck? Does boiler go through any ignition process with htg only demand? If you've changed diverter, did you make sure the valve pin was clipped in the motor arm? If you've a built in clock, try bypassing it? If you've a room stat, remove the connections & link terminals to eliminate external faults?
Thanks for the input G&W..... We don't have room stats and i have reset the clock.... I've checked that the motor is located on the valve pin and it is, I ran a volt meter over the connections on the pcb and get 240 volts on pins 5&7 (Hot water) but not on pins 5&6 (central heating mode) i decided to supply 240v to pin 6 to see if the motor would kick in which it did so the motor is working fine... Does this point to the PCB being faulty or is there something else that tells the pcb that i've opened the stat on the rad and to supply 240v to the motor? Cheers Jonny
Yes I'd go with board, their a basic boiler really, I'd phone them just to confirm though, you can't return PCB's so better safe than sorry
Just an update, i ordered the PCB which i installed yesterday but unfortunately its still stuck on water, any ideas what else may be causing this issue? This combi is going to be like triggers broom from only fools and horse lol
Hi Me thinks it's time to step back and start with basics, Are you sure you have a switched live for the heating? I see in your previous post a reference to the rad valve starting the boiler? Check out the diagram, you are obviously competent with a meter, the symptoms are no demand for heating, ? Check and check again, don't do a Rodney here Regards Peter
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