Main 24 Combi - Overheating?

[FlowGas]

Hi everyone,

I have a Main 24 combi which fires up for 30secs and then cuts out when central heating is called. DHW is working fine. Some adivce or direction would be much apperciated.

Thanks.

 

[Billy Bob Bob]

filter in the returns probably blocked its located in the return iso valve behind the half inch silver cap or filling loop if fitted,remove the filter and clean it

 

[FlowGas]

Thanks Gas Man.

The best way to approach this? Drain down the system or is there an easier solution?

 

[newcastle phill]

Knock F+R isolation valves off and drain boiler if its the ones i think hes thinking of..