No HW & No CH

[Nilou9]

Hi some advice please, there is no flow of hot water to either the Hot water cylinder or the radiators. System has been working fine for years with no changes made, consists of Potterton Netaheat boiler Grunfos pump and Honeywell 4073A 3 port valve. Boiler fires up pipes immediately ajacent to it get hot yet all 3 pipes at 3 port valve are cold as are the pipes either side of the pump. after a few minutes boiler shuts down (over temp I assume) pump sounds like its working but body gets hot, strange noises coming from 3 port valve. I suspect the 3 port valve but how do I confirm this? can these valves get into a position where water cannot flow into either CH or HW?

Many Thanks in advance

 

[namsag]

No there will always be one of the circuits open.. Take centre screw out of pump and makesure it is spinning also check header tank has water in it,
Make sure system has water in it you may have a blocked cold feed

 

[gas4you]

Sounds like pump knackered or stuck. Check for 230V at pump terminals.

 

[Nilou9]

Thanks Namsag, you were quite correct lack of water in the system, blockage in cold feed.

Many Thanks for the replies