Mini C28 DHW fail - sounds like crunching gears!

[rocketchef]

hello,

Wife decided to bleed the radiators today without telling me (she saw my Dad do it??), resulting in a loss of system pressure.

I've no idea what the original pressure was, but I set it back to around 0.7 bar cold, and CH is working fine.

However.... DHW is not working. Shortly after turning on HW tap, boiler makes incredible loud noise akin to crunching gearbox which goes away as lock-out light goes on.

Any suggestions? That noise is scary enough to make me call an engineer, but I thought I should check its not something simple first, like air.

C28 is an older one. Not sure how old, but +5 years and not an HE.

Ta!

 

[Agile]

Set pressure to 1.5 cold.

I really dont know why people love to bleed rads whent ehy dont understand that it needs to have the pressure increased afterwards. It causes problems and is rarely needed.

Its difficult to guess whats wrong without seeing the boiler because the obvious parts the pump and fan are also used on CH.

The engineer sould have no problem though.

Tony