Hot Water Luke Warm After Powerflush

[cr0ft]

Hi all.

I've recently powerflushed a very old CH system that was full of corrosion. By full I mean a blocked cold feed and the boiler was making kettling noises and sending boiling water into the loft tank after a drain down to change a ground floor radiator. Worst system I've seen.

Anyway, the system has been refilled and the CH system seemed to be working ok, although the radiators weren't getting as warm as I would have hoped for. The customer has phoned today and said that her hot water hasn't been that hot either for the last few weeks.

Does anyone with more experience than me have any idea what this could be? I can turn the boiler thermostat up but I'm not convinced that will affect the temperature of the hot water, only the speed it takes to heat it up?

Any advice appreciated.

 

[Mbear]

Are zone valves fitted?

Start with testing the hw zone valve.

 

[cr0ft]

Hi, 2 zone valves are fitted, for CH and HW. I'm going to take a look tomorrow morning. I can't remember the configuration of the pipework from the coil in the cylinder, but I'm thinking perhaps this is airlocked as it's an indirect cylinder.

Will keep you updated!

 

[Mbear]

Hi, 2 zone valves are fitted, for CH and HW. I'm going to take a look tomorrow morning. I can't remember the configuration of the pipework from the coil in the cylinder, but I'm thinking perhaps this is airlocked as it's an indirect cylinder.

Will keep you updated!

Did u leave the zone valves open manually while powerflushing and refilling?

If not it may be airlocked between the zone valve and the return

 

[Billy Bob Bob]

i agree when you drain a system with motorised valves you need to spring and lock the motor to stop air locks

 

[mutley racers]

Spring them? What does that mean? Nice bit of advice though guys. Shall remember that.

 

[Mbear]

Spring them? What does that mean? Nice bit of advice though guys. Shall remember that.

Just means manually lock open the valve.
'there's an internal spring in the valve'