Vaillant Turbomax VUW 242E - inconsistent hot water

[nickldn]

I wonder if anyone can help me with a question about the Vaillant Turbomax VUW 242E 282E boiler's ability to heat water and run the central heating.

The boiler is in a one bedroom flat and when the central heating is on and the bath is run, the water is at best lukewarm.

When water in the bathroom basin, or kitchen sink is run it seems to be a lot warmer than in the bath.

Am I right in thinking that the water flow rate to the bath is higher than to the basin, or sink? Is this perhaps why the boiler can't cope with that and the central heating at the same time?

Does anyone know if the boiler would prioritise hot water over central heating, or vice-versa?

Any help would be greatly appreciated.

Nick

 

[holty]

with the cold we have at the moment and the flow rate of the boiler, id imagine your bath runs in 22mm. id hold back a bit before worrying about the boiler. its worth getting the boiler serviced though.

 

[wedge69]

Hi, we have the same boiler as you. Sometimes it seems the hot water in the bathroom sink is colder than the water in the kitchen sink.

I have found that if for the first few minutes you only open the bathroom tap a little bit, the water will get a lot hotter, then open it up all the way. I think it actually suggests this in the manual.

Or you could always turn the hotwater dial up on the boiler a bit.

 

[kevplumb]

Does anyone know if the boiler would prioritise hot water over central heating,

it does

 

[bengasman]

your boiler does not so much prioritise, as switch to hot water on demand and turn off the heating.
might sound nit-picking, but it explains why the rads get colder when you fill a large bath.
just don't run the hot at full flow, and you will find it gets hotter.