Oil Combi Boiler Hot/Cold/Hot

[Freddy1O]

Hello. I have an oil fuelled combi boiler and the hot water starts hot, then goes cold for a few seconds and then back to hot... Is this right? Thank you.

 

[ShaunCorbs]

Nope is it on all outlets ?

 

[Deleted member 120897]

Does it stay hot after that initial issue, or keep going hot and cold?

 

[Freddy1O]

Does it stay hot after that initial issue, or keep going hot and cold?

Yes, once it gets hot for the second time, it stays hot.

 

[Freddy1O]

Nope is it on all outlets ?

Seems to be only noticeable with the showers...

 

[John.g]

Oil fired combis I think produce DHW at ~ 80C and reduce it to 60C with a TMV, if the HW from your hot tap is very hot (80C) then the TMV may be faulty and the shower(s) TMVs over compensate with cold water initially and then stabilize.