Jaguar 28 Problem

[grangeta]

Can anybody help me with this problem.

Boiler:
Jaguar 28 (Model 28KTVJ15) supplied by Plumb Center and is believed to be about 5 years old.

Diagnostics detail
1) No error codes displayed on control display.
2) Boiler pressure ok at 1.1 bar.
3) Boiler appears to fire up correctly on cal for CH or DHW
4) CH is working fine.
5) DHW delivery problem.

The Problem
Boiler fires up on call for DHW, water heats up then alternates Hot, Cold, Hot, Cold.

Any help would be greatly appreciated.

Terry.

 

[heatingman]

plate ex is partially blocked, inject some ferroquest or similar into system and run for few hours, if doesn't clear the ex will need to be removed and soaked/cleaned in something stronger.

 

[gas4you]

You'll need to keep the boiler in DHW mode to do this, otherwise the cleaner will not circulate through the system side of the plate.

Personally I would take it out to clean seperately.

 

[grangeta]

Thanks for the replies heatingman and gas4you. My preference willl be to remove the secondary exchanger to work on it.

Thanks big help.

Terry.