Hot Water not as hot as it used to be

[webbchr]

I have an Alpha 900 combi boiler (pressurised system, no header tank) which has been working fine for about 5 years. Recently the hot water it has delivered has been cooler than in the past and the temperature varies from warm to cool while in use. This is especially noticable when showering.

If I sit by the boiler when hot water is being drawn I can see the burner flames varying in strength over time in synch with the temperature changes.

Other symptoms:

The boiler now makes a faint moaning sound when in use.

The Radiators get hot (much more noticably so) when water is being drawn.

[Phil]

The diverter (hydraulic) valve in the boiler is most likely passing hot water that should be destined for the secondary heat exchanger (for DHW) to the rad circuit. You have a choice of getting it replaced once diagnosed, or - as I did

- stripping it down & cleaning the valve faces, and resetting the spring length that closes the CH circuit. Worked for me.

Cheers,

Phil.

[webbchr]

Thanks Phil. I'l investigate this route further.

Regards,

Chris W

Phil wrote: