vallant turbomax pro hot water fluctuation

[sterfer]

Hello,

i wonder if anyone can help. 18 months ago I had a vaillant turbo max pro fitted. This has worked fine until now 3 days ago I noticed that
when the hot water is running it fluctuates between hot and luke warm.


all the indicator lights light in the correct order, the central heating is working and the whole system was new when installed. Pressure is
in the green as recommended.

Any ideas?

 

[ChrisR]

Has it always been the same?
Try it with more HW taps on
Ideally measure the rate of water coming out of each tap and add them up.
(Time them for 1 litre and tell us if you like)

If the flow isn't restricted by the taps then it's probably scale in the secondary (ie the tap water)heat exchanger.

How long does it stay hot/cool?

With the taps on, listen very carefully with your ear to the boiler . Can you hear a tick every few seconds, perhaps 5secs, tick, 3 secs, tick, 5secs, tick etc?

 

[sterfer]

hello chris , thanks for your reply . in answer to your questions turning on more than one hot tap makes no differrence idont think flow is restricted in any way and no clicking sound from boiler but a rushing sound every 10 seconds or so. any further ideas greatly appreciated.

 

[ChrisR]

a rushing sound every 10 seconds or so

is drowning the little clicks! (5 + 3 = 10, ish)

The noise is from near-boiling, also from lack of circulation.
(Does it make that noise on CH at all?)
OK, sludge confirmed. Different bods will have different ways of dealing with it. Where are you? One of us might be local.

ps, Your installer was a cowboy.