Gloworm combi boiler help!!!

[JAY123]

Some advice would be very much appreciated.

Our Gloworm Ultracom 38CXI combi boiler recently developed a few issues.

Recently some our taps/shower but not all of them will run hot initially and then run cold after around 2 minutes of running hot.

The heat exchanger was replaced by our plumber and the issue is still present. List below of which taps/showers have this problem and don't have this problem in the house-

Downstairs bathroom Mira thermostatic shower- HAS THE PROBLEM
Downstairs bathroom sink mixer tap- HAS THE PROBLEM
Downstairs utility sink mixer tap- DOES NOT HAVE THE PROBLEM
Kitchen mixer tap- DOES NOT HAVE THE PROBLEM
Upstairs bathroom Bath mixer tap- HAS THE PROBLEM
Upstairs bathroom sink mixer tap- DOES NOT HAVE THE PROBLEM

As you can see from the above, half of the taps have this issue where as the other half do not.

We also have an issue with the pressure on the boiler going up from 1 bar to close to 3 bar within 2 hours, it goes up even after I have turned off the heating and made sure no one turns on the showers or runs the taps in the house.

If anyone could help with any advice it would be massively appreciated.

Thanks

 

[Deleted member 120897]

If the pressure is going that high with the heating on then there‘s an expansion issue. As for the intermittent hot and cold - sounds like a mixer tap/valve passing.