Ideal logic + combi 30

[Jacko]

Hello Guys
Help needed again problem on the above boiler. Hot water works fine however the heating comes on temp on display goes to 70-80 and the boiler turns off.
None of the flow or return valves get hot although the main heat exchanger does.
DV motor operates, even with the motor disconnected and the DV pin manually pushed in the boiler does the same..... what is causing the boiler to overheat and switch off????
Pump operates, tried another pump same fault.????

 

[Mastermixlee]

Sure the isolation valves are clear and haven't broken inside?
Could be blockage in flow or return too.

What's the system pressure reading?

And of course the regular question, are you a GSR?

 

[Riley]

He is GS we are just waiting for admin to update rights. Feel free to help or maybe PM to keep out of public view

 

[Mastermixlee]

Same as me then

Will help where I can and will PM if anything that is likely to involve delving into GSR territory

 

[Riley]

Not ideal I know chaps. We are trying though promise

 

[AMGasServices]

I’d check the system filter if it not full of muck, I’ve not worked on one recently but I think they may have a mesh filter in the flow or return valve check that.

I know the earlier models had an issue with the diverter valve.

Check the resistance on the CH thermistor and if possible link out any control.

 

[Jacko]

Thanks for your help guys. The flow and return valves are opened..... could they break in closed position if they haven’t been touched by the customer???
The water pressure is 1.5 bar.
Will open up and visually check the flow and return valves, will also check the built in filter if I can find it....... the boiler reaches temp and just a down so I assume the thermistor is ok....
Just never had a circulation issue like this where the flow valve doesn’t even warn up

 

[Riley]

As everybody now has their badge I have moved this to the relevant forum

 

[Jacko]

Hello All a bit of an update....... flow and return isolation valve are open on the boiler.
Then.... I pressurised the system to 1.5 bar and isolated the magna clean valves, I drained down the magna clean then when I opened up the top magna clean isolation valve the magna clean started to fill up, so I closed it, then with the top magna clean isolation valve closed I opened up the bottom magna clean isolation and there was no water coming through, both magna clean isolation valves work......is that proving there is a blockage in the system? Hence the boiler heating circuit overheating?

 

[Riley]

I should say so mate. Is it on return?

 

[Jacko]

Yes on the return........ just can’t get my head round why the boiler in heating mode does not get rid of some heat even if it’s 1 metre of warmth from the flow pipe?????

 

[Riley]

Does flow get hot on the way out??

 

[Jacko]

No the only thing that gets hot is the actual main heat exchanger!!!!!

 

[Riley]

Diverter is definitely shifting??

 

[Riley]

Sorry if you’ve said that already

 

[Jacko]

Defo shifting, I have removed the motor and manually pushed the pin in..... no apology required

 

[Riley]

So no heat transfer to DHW when hearing called

 

[Aire]

I'd say definite blockage, are you sure the blockage isn't in the magna clean? Opening the bottom valve and getting no water through would suggest either the valve itself is blocked or the blockage is close by.

 

[Riley]

Inclined to agree

 

[Jacko]

No heat transfer to Dhw.......
Both magna clean filters are opened, I removed the push fit magna clean and visually checked the bottom isolation valve

 

[Jacko]

Sorry both magna clean valves

 

[Aire]

No heat transfer to dhw, at the start of the thread you said hot water works fine. Are you saying now it doesn't?

 

[Aire]

No heat transfer to Dhw...
Both magna clean filters are opened, I removed the push fit magna clean and visually checked the bottom isolation valve

But if your getting no water through the bottom valve then that would suggest a blockage between the filter and the last rad on the system.

Actually, what side of the system is the bottom valve on? The return to the boiler or the return from the radiators?

 

[Jacko]

Sorry dhw works fine.....

 

[Jacko]

Return to the rads