Worcester Bosh 28i junior hot water fluctuates

[Nicholas]

Hi Marco,

with this boiler it tends to indicate a blocked plate heat exchanger.

You will need to take the cover off and whilst running the hot water feel the temperature of the outlet at the top of the kebab heat exchanger and compare this to the temperature coming out of the hot water at the bottom of the boiler with hot water being demanded and the boiler on.

With one hand at the top and one hand at the bottom you can compare the temperatures they should be the same. If not you will need to remove the plate heat exchanger.

A lot of engineers will remove the return manifold to gain access but you can also cut the hot water outlet pipe to gain access and remove the unit. You will need to isolate the boiler at the bottom from the heating circuit and isolate the cold water inlet.

Part required is 87161066960

Let me know how you get on

Nick