Combi Boiler hot water problem.

[Greenie9657]

good evening all,

This one has really stumped me and I cannot work out why!!

When I have the heating on, everything is fine. When I run the hot water either for a shower (mixer) or from the taps, the boiler reset light flashes and I have to reset it. This occurs within 5 minutes of the water running.

I have a Worcestershire 24i junior. It's What came with the house when I bought it 3 years ago. I will upgrade eventually to something more beefier but it's been working fine until now.

I cleaned the central heating system over the last week and now it has the inhibitor in but that's the only work I have carried out.

Any information would be great

Regards

 

[Agile]

Well, you have not told us what we would want to know.

Did you clean the system BEFORE or AFTER the light started flashing?

And WHY did you decide to clean it?

And WHAT did you clean the system with?

Tony

 

[Greenie9657]

Hi Tony,

I refurbed a bedroom so had to drain the system to move a radiator. When i drained it there was evidence of sludge so I cleaned the system, left the cleaner in there for a few days then drained the system, flushed it, and topped back up with the inhibitor.

I used sentinel x300 to clean and x100 to inhibite. But like i said, the boiler works fine with the heating on, it's just the hot water demand.

Thanks

 

[Greenie9657]

Just in case a picture helps, here's my boiler

 

[jeff the gasman]

It could be a partially blocked plate heat exchanger or a thermistor breaking down. A decent boiler guy would pinpoint the problem.

 

[Greenie9657]

Is there any checks I can do with a multi metre that you know of?

 

[gigz]

Does the boiler need resetting if the heating is'nt on (i.e. From cold)? When was it last serviced or had the co/co2 checked ?

 

[Greenie9657]

Yeah I've tried all combinations. Whether the heating is on or not, the boiler needs resetting when hot water is demanded. I managed to get a gas man to fit me in tomorrow so he's going to come round to take a look. Hopefully it's nothing too bad.

If I was to replace in the new year what would be your recommendations?

 

[muggles]

Could be air in the top of the heat exchanger causing it to overheat if you've drained the system. There's a bled vent on it, but you're not really supposed to take the cover off so you'll have to wait for your engineer I'm afraid

As for a replacement, if you want another combi then an Intergas Eco RF 36 with a ten year warranty, or an Intergas Combi Compact HRE 36/30 if you want a seven year warranty.

 

[Greenie9657]

Many thanks muggles. I would defo stick with a combi. Do
Both of your suggestions have a good flow rate? At the moment with mine, if someone is in the shower and another hot tap is put on somewhere the shower cuts out, ( thermostatic bar mixer)

 

[simond]

You won't need a new boiler. The one you have isn't very old, and you broke it by moving the sludge through the plate heat exchanger.

 

[Greenie9657]

So how do I unbreak it simond?

 

[Agile]

X300 is for cleaning NEW radiator systems.

For sludge you need X400 or X800 depending on how quickly you want to clean it.

But whilst it may help a little it is not usually going to make much difference to a plate heat exchanger.

Plates normally have to be removed to clean and that can be very difficult on some Worcester boilers!

Tony

 

[simond]

You take the plate heat exchanger out and either clean, or replace it. As Tony says, bit of a faff. Get a full set of O rings first as it will be emotional without them.

 

[Agile]

I fitted a new Worcester 38cdi Classic today.

It has a very wide plate HE but it looks like a big job to remove it with taking the boiler off the wall.

Come on someone, tell me how long it takes?