Vokera Excell 80sp hot water problem

[HRHKaydawg]

Hail!

Wonder if anyone has some insight here.

Have an old Vokera Excell 80sp. She's a fine old machine but recently the hot water has been running luke warm on full flow with the burners firing constantly. The central heating is fine. I've cleaned out the diverter and replaced diaphragms, seals, o rings etc. Replaced thermistor. Flushed out and descaled domestic heat exchanger. And water is still running luke warm under 50% on the gauge though when I slow down the flow the water heats up. To get a decent bath I have to keep the water on a very slow pour and that with the hot water temp control turned up.

Would be so grateful for any wisdom on this.

 

[diamondgas]

Hi HRHKaydawg & welcome to the forum ... It sounds like you're a compitent DIYer would that be true to say? reason I ask is because there are tests to do on these old birds that involves interupting gas seals and testing pressures as well as electrical components that effect these... Do you posses a manometer and know how to use it?

 

[HRHKaydawg]

Thanks Diamond for getting back so soon.

Yep you guessed it - able but no plumber. Alas don't have and don't know how to use a manometer. Can see what it does but all too arcane for me. Looks as though this may indeed be beyond me. One bit of advice from Vokera was to check the cold water venturi. But don't know where this lives in the machine. And looking at the assembly manual there's nothing called this. Have you any idea? And does that make sense to you?

 

[diamondgas]

The venturi will live in the cold water diaphragm section I'd imagine *shrug* But your boiler is detecting water flow and lighting up so doubt it'd have anything to do with that ... I'd suspect you may have problems with the modulation on the burner, you wouldn't be able to check that without messing with the gas side of your appiance ... Your choice I'd say is to get some one in to check this or considder renewing? She owe's you nothing.

Cost wise you could be looking between £50-£200 at a guess

 

[HRHKaydawg]

Hey Diamond G

Thanks again for the help. Well...here's the thing. I read once 'Sometimes you've got to go a long way outta your way in order to come back a short way correctly'. Having spent a day and a half with my head in the boiler and seeking advice from your good self and another plumber I know, it dawned on me that the only thing that could be wrong was the gas flow. There's a yellow lever underneath the boiler which is very accessible and sits just above the dish draining tray on my sink. What I wondered was - had that lever been pushed forward (semi closing the gas flow) when over stacking dishes and pots. Went home, headed straight for boiler and lo!...

Well the old bird got a fairly thorough servicing at least. Sentence doesn't sound good...but it's true. As you said she owe's me nothing.

Thanks again - really helped enlighten me.

 

[diamondgas]

Are you saying the gas control was semi closed?

Have you got it sorted now? Sounds like you have

 

[HRHKaydawg]

That was it. I pulled the lever back which fully opened the gas flow.

Massive relief.

The diverter needed a cleanout as it happens - it wasn't totally switching the hot water from the central heating. so that was a positive result at least.

Thanks again.