my vokera xl80sp combi boiler is fine with everyting except the bathwater which runs only lukewarm. The shower above the bath runs hot. The water heating gauge is turned to max. Can anyone help?

Julie Thompson, November 2007

Julie, if this is not yet solved get someone who knows what they are doing and who is legally allowed to touch gas boilers, to check the gas rate for hot water. This should indicate which part is not working properly (e.g. a temperature sensor) or even identify that the boiler has never been properly set up. There are so many reasons why this problem might occur that it is not possible to diagnose it effectively without undertaking tests on site. Turning the cold inlet on the boiler down might appear to help, but you shouldn't need to do this!

Paul Young - Portland Plumbing, January 2008

Hi Julie
I also have a Vokera boiler (Linea 24)and had a similar problem when it was first installed. From it being new, the central heating was fine but we couldn't get hot water, only warm, despite the control being set to maximum. Because it was new, we got Vokera out twice to it. Their engineers insisted there was nothing wrong but there obviously was.
We got quite desperate as we were having to boil a kettle to wash up and baths were quick affairs.
The second time we had it serviced, we got a local firm who specialise in servicing only two makes of boiler, one of which was Vokera. We told the engineer of our problem and, as soon as he opened the boiler, he said he could hear what the problem was. Now, I'll explain this as well as I can, bearing in mind that I know little about plumbing.
Apparently, there is a valve which stops water from leaking back from the heat exchanger. Having looked at my installation instructions, there are valves mentioned called "heating flow and return valves".
Anyway, this valve had been installed back to front so that water was leaking back before it could be properly heated. The engineer could hear the hissing sound as it leaked. He fitted a new valve the right way round and the rest, as they say, is history. We now get hot water both in the kitchen and bathroom.
I'm not sure if this helps you but it may be worth a try to mention my experience next time you have the boiler serviced.

Linda

Linda Marsden, November 2007

Turn the flow rate down on the cold water inlet tap to the boiler so that the fully open hot bath tap water temperature is OK. You may need to turn it down further later as winter makes the incoming water colder. Check that the hot water is always heated and is not going hot-cold-hot-cold as it fills the bath.

c, November 2007