Broadback wrote:

A.Lee wrote:
Broadback wrote:

My Vaillant Turbomax Plus boiler is having problems supplying hot water.
The central heating is fine ....
Does it continually go hot then cold then hot etc?
If so, possible hot water heat exchanger blockage - quite common
apparently..

It alternates hot and cold.

I had the same thing, starting around this time last year.
DHW Heat Exchanger was cleaned out, then changed after a few months,
still no good, turned out to be either the primary heat exchanger or the
pump.
Power flushing and chemical treatment did not cure the fault.

It was 10 years old, had never been very reliable, so I bit the bullet
and had a new boiler.
It is possible that a flush out of the DHW HE would cure your fault.
On mine, it took 10 minutes or so to get the HE out, so a fairly easy
task, no idea what it would be like on your Valiant.
Alan.
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