Vokera Line Max HE - Hot Water Problem

[JSC]

Last week we had our old Worcester Highflow boiler replaced with the Vokera Linea Max HE, when the former finally packed up. Since having the Vokera fitted our hot water has gone from scorching at first followed by hot (with the Worcester) to just 'hot' for the first minute followed by luke warm with the Vokera. It's impossible to run a 'hot' bath as the water just ends up running cold. I have also found that it takes a lot longer for hot water to flow from the taps - almost a minute in the en suite (not good when on a meter). although the central heating seems fine, it would appear that this boiler is far worse when it comes to hot water. I have contacted the installer (Corgi and Vokera registered) and he has suggested fitting a pressure reducer as our mains pressure is quite high. Does anyone know if a) this will solve all of the hot water problems and b) if the reducer will substantially effect the excellent shower pressure we currently enjoy?
Any ideas and advice would be much appreciated

 

[Paul Barker]

I can't get data from Vokera except flow rate should be 18 lpm so can't see why you should have a problem.

 

[DP]

I would certainly get a pressure reducing valve. I have seen the main and secondary HE fail due to excessive pressure.

I would get the system water analysed. Suspect system pollutasnts are now resident in the HW HE.

This boiler should be able to fill a bath in three minutes. You can thereafter have a bath every 10 minutes.

 

[JSC]

Thanks for your replies. I think you have confirmed a problem and I will certainly go with the pressure reducer. I don't understand where the system pollutants would have come from though, the boiler was only fitted on Thursday?

The bath hot water pressure isn't as good as downstairs, and obviously with the hot water running at reduced heat, I think we could just about manage to fill our bath with luke warm water in about 10 minutes. (We do have an extra deep bath mind)!

 

[DP]

When a new boiler is fitted, the existing installation must be chemically cleansed. If it is not, sediment will move with primary water to block narrow waterways.

It does not matter when the boiler was fitted, all that needs to happen is for this muck to move and block out the HWHE. Thereafeter, while you will get good flow of tepid water from the hot tap, it will fluctuate between tepid and hot.

It is also possible, the boiler has not been commissioned correctly. Check the Benchmark and compare the figures with those in the manual.