Tundish overflowing during hot water

Hardware Heatpump
1

Hi

Not related to efficiency here, but has anyone had their pressure topped up by an engineer only for the tundish to then overflow?

thanks

Godfrey

2

I’d call your engineer!

This is not normal and should not be ignored; this is safety equipment!!

Some causes may be easily rectified but there may be a hazardous fault.

One possible cause is low pressure in your expansion vessel and your engineer should be able to check and rectify this easily.

3

This indicates that the hot water cylinder expansion vessel is not working properly. It will either need to be re-charged with air or most likely replaced. Call an engineer ASAP as it’s a potential safety issue. There’s nothing heat pump specific about it, a boiler engineer will be able to do the job fine.

4

Thanks both. Got someone coming on Thursday!