bath tap not hot when fully open

[jockdee]

hi all.
having a problem with my mixer bath tap. only get hot water up till it's about half way open then it runs warm/cold and it takes about 15/20 mins to run a bath.
it's fed off a 2 year old combi boiler and bath and taps are only 6 months old.

 

[shambolic]

What size of boiler hot water output and flow rate?
If you have a boiler with a 35deg rise at 12litres a minute and the water from the street is only 5 degrees cold then you WILL only get 40 at the tap if open full and less if even quicker flow.
It's a drawback of a combi boiler with lower hot water output.
Only solution is to drop flow rate(how quick you run tap) to give a greater rise than 35degrees.
Your technical data in the boiler manual will tell you this. Or give us make and model?

 

[jockdee]

it's a vokera compact 29he mate. thanks for replying. it worked ok with the old tap.

What size of boiler hot water output and flow rate?
If you have a boiler with a 35deg rise at 12litres a minute and the water from the street is only 5 degrees cold then you WILL only get 40 at the tap if open full and less if even quicker flow.
It's a drawback of a combi boiler with lower hot water output.
Only solution is to drop flow rate(how quick you run tap) to give a greater rise than 35degrees.
Your technical data in the boiler manual will tell you this. Or give us make and model?