Bosch combi boiler playing up

[AceOfHearts]

Got it back in last night, but run out of fibre washers for the last two connections

I am popping out today to get some more, but will not be able to finish the job off until tomorrow morning (at work)

Once this is done the boiler will have had a de-scaled heat exchanger, new diverter valve and new gas valve this year. Hopefully it will stop playing up for a few years after this

I will get some photos too if that is of any help?

Edited by AceOfHearts on Sunday 2nd June 09:38

[AceOfHearts]

It is fixed!

Water gets hot and stays hot. Very happy and no leaks

The calorifier was actually quite easy to get out as well (about an hours job) so i may start doing it every couple of years to keep it clean.

[Rickyy]

Interesting, was always told not to bother attempting to clean out the calorifier, may give it a go next time.

[Morleym2002]

VERN UK said:

Post up the exact model for starters

Hi you seem to know about this boiler and I need a little help diagnosing a problem. I have a 35CDi mark 1 (no diverter valve but two pumps in boiler) and am having problems maintaining a steady temperature at my shower. Originally suspected the flow switch but that has now been replaced. I suspect the real problem is a partial blockage of the plate heat exchanger. Symptoms are fluctuating dhw temp, rads start to warm up after a while even though central heating is not being requested. On the boiler the lights are as expected, dhw on, flame on but after a while Ch light comes on too, at this point the shower gets very hot. I hope you can help.
Regards Mike

[Rickyy]

Been a while since I've worked on one of these.

But it does sounds like an overheating issue, CH pump probably comes on to dissipate excessive heat build up.

If you can get to the PHE, feel the flow and return pipework to it from the main hex, if there is a noticeable difference in temps, this indicates the PHE could be blocked.

It could also be a failing pump.