Baxi boiler help

[dave7108]

My baxi is only 4 years old but today the heating is fine but the hot water is either non existent or luke warm for a few seconds then cold. Baxi can't come out till Friday. Any ideas what it could be?

[sherman]

Divertor/3 way valve.

If your heating is fine and hot water is not. Its most likely that.
It manages flow between heating and hot water. Its broken and wont allow the boiler to switch between the 2.
Not much you can do without an engineer really

[Crumpet]

It depends how competent you are as it’s a pretty easy job to swap out if it is the diverter valve; my Baxi Duotec 2 is now 16 years old and I’ve done a couple of them.

[megaphone]

What type of Baxi boiler do you have?

[CambsBill]

We have a Baxi combo boiler and twice now the heat exchanger for the hot water side has become blocked with black gunge, this despite having Fernox in the system and a Magnaclean. The symptoms are as per the OP but with added pops & bangs from the boiler before it throws up an error code.

If it is this, the h/e can be reverse flushed & then cleaned with acid rather than replacing.

[megaphone]

CambsBill said:

We have a Baxi combo boiler and twice now the heat exchanger for the hot water side has become blocked with black gunge, this despite having Fernox in the system and a Magnaclean. The symptoms are as per the OP but with added pops & bangs from the boiler before it throws up an error code.

If it is this, the h/e can be reverse flushed & then cleaned with acid rather than replacing.

When the boiler was fitted, was the system power-flushed to remove the black crud?

[dave7108]

It's a duotec 33. Before installation ( which replaced an identical unit id had for 10 years or there about) all the rads were replaced. So the system should be pretty clean. It's had fernox in it and also drained and cleaned with new fernox (but not powerflushed) on a yearly basis. I'm quite ocd on keeping the system clean as the old boiler was not looked after very well. It also has magna clean system which I clean out every few months.

The heating works fine and fires the gas up instantly. The hot water produces no flame unless you keep turning the water on and off and only then it produces luke warm water.

[CambsBill]

megaphone said:

CambsBill said:

We have a Baxi combo boiler and twice now the heat exchanger for the hot water side has become blocked with black gunge, this despite having Fernox in the system and a Magnaclean. The symptoms are as per the OP but with added pops & bangs from the boiler before it throws up an error code.

If it is this, the h/e can be reverse flushed & then cleaned with acid rather than replacing.

When the boiler was fitted, was the system power-flushed to remove the black crud?

I have no idea, it was there when we moved in (& only a couple of years old at that point)

[Nezquick]

Crumpet said:

It depends how competent you are as it s a pretty easy job to swap out if it is the diverter valve; my Baxi Duotec 2 is now 16 years old and I ve done a couple of them.

This - I bought a Honeywell from Ebay and fitted it within the hour. Mine was just the electric motor which had gone though and not the valve itself.

[GasEngineer]

Nezquick said:

Crumpet said:

It depends how competent you are as it s a pretty easy job to swap out if it is the diverter valve; my Baxi Duotec 2 is now 16 years old and I ve done a couple of them.

This - I bought a Honeywell from Ebay and fitted it within the hour. Mine was just the electric motor which had gone though and not the valve itself.

You're thinking of a (mid position) valve in the pipework. The diverter valve is an internal part within the boiler.

It's a grey area if you are working on your own gas boiler at home but it is illegal to even take the cover off a boiler if you are not Gas safe registered. The myriad "how to fix it" videos on YouTube don't help.