Boiler Hot Water Temperature Fluctuation

[Adam10]

I have an issue with a plumbed in mains pressure mixer shower. When running the shower the boiler will cycle to a very nice warm temperature around 56degC(?) and then switches off (as it is up to temperature?). The shower will then use up its reserve of warm water then start to refill it. Trouble is by the time the boiler kicks in again to maintain the temperature it has dropped to around 30 degC, and the shower feels freezing cold until it warms the water again then the cycle will start again. Roughly every 5 minuets.

The boiler is Vokera Linera 24 Boiler, recently serviced and last year had most of the major components replaced whilst trying to diagnose a different issue.

What would be the probable cause and how could I resolve this to give a nice constant flow of warm water to the shower?

Many thanks in advance
Adam

 

[RoryD]

One of two things, a restriction in the shower head or, more likely the minimum burner pressure has not been set correctly. There is an upper and lower pressure bracket, because your shower will allow a lower flow, then the burner pressure should modulate down to prevent overheating. If the pressure has not been set low enough, then the temperature sensors will turn the burner off until it cools down...and then start up again. the effect is hot water followed by cold

 

[Adam10]

One of two things, a restriction in the shower head or, more likely the minimum burner pressure has not been set correctly. There is an upper and lower pressure bracket, because your shower will allow a lower flow, then the burner pressure should modulate down to prevent overheating. If the pressure has not been set low enough, then the temperature sensors will turn the burner off until it cools down...and then start up again. the effect is hot water followed by cold

Ok great. Ruled out a restrictions so I'll have a look down the pressure route. Is this somthing that is fairly easy to do by hand? Anything I should be looking at in the manual? I've had a good dig around at parts in the boiler before although am I best getting an engineer out to sort?

Many thanks
Adam

 

[RoryD]

Ok great. Ruled out a restrictions so I'll have a look down the pressure route. Is this somthing that is fairly easy to do by hand? Anything I should be looking at in the manual? I've had a good dig around at parts in the boiler before although am I best getting an engineer out to sort?

Many thanks
Adam

Don't want to be a jobsworth mate, but if you're not Gas Safe trained you can't work on a gas appliance (it breaks the law). Think u need an engineer<:[