Baxi Eco 80 CH Running When Calling For Hot Water

[d4nnyk]

Hopefully someone can help me. I have a Baxi Eco 80 Combi Boiler and although the Heating is turned off, the radiators heat up when running the hot water tap.
I have replaced the diaphragm in the divert values and this has not resolved the issue.
I have noticed that when I call for hot water both pins on the diverter value come out and trigger the micro switches, should only the water pin come out (as the heating isn't on).
The central heating side is fine and when running only the heating pin comes out of the diverter valve.

Am I right in thinking that thing has probably seized in the divert valve and a new one is on the cards?? or could it be something else less expensive??

Many thanks in advance

 

[linkyplumb]

Probably just as easy to buy the complete diverter valve.

Mind that PCB when you take it out though

 

[d4nnyk]

Thought that would be the case.

Can you comfirm that I am right that only one pin should come out of the valve at a time, unless you have the CH on and the Hot Water Tap on

Many thanks

 

[45yearsagasman]

When hot water is used both pins move.The front one is the call for hot water and the one on top is proving that the pump is operating.If you have some diy skills it is possible and a lot cheaper to recon the diverter valve with a service kit,all done from the front.I never replace the whole diverter.With CH on only the top micro switch should operate.

 

[d4nnyk]

Hi thank you, I have done a recon on the diverter valve, replaced both diaphragms etc.. but the radiators still heat up when running hot water.

Am I safe to say that a new diverter valve is needed or could it be something else? don't really want to spend £80 on a diverter valve and find out that doesn't fix it.

 

[45yearsagasman]

Changing only the diaphragms is not a fix for your problem.The internals of the valve require attention and can be done with the correct service kit.

 

[d4nnyk]

Do you know what the correct service kit is?? and where I can source one as all i can find is diaphragm kits

Many thanks

 

[d4nnyk]

Just managed to source a complete diverter valve unit including DHW valve for £75 so going down this route, the service kits (for other diverter valves) come to £50 ish so thought mine must be the same region, so for saving time and hassle, the new valve route is the best option, just hope it fixes my issue.

Thanks for your help

 

[Agile]

The rear manifold section is not following the front hydraulic actuator.

I have tried cleaning this type in the past and in one case, for a friend, I even boiler the parts in citric acid to 100% clean them and then reassembled then with silicone grease.

That worked for just a few weeks! So I now always replace the whole valve when it has that problem.

I expect the the spring which is compressed at rest, loses its strength and cannot overcome the moving resistance required.

Tony

 

[d4nnyk]

Thanks for your post, gives me confidence that the new valve will resolve my issue and it will be £75 worth spent.

Many thanks

 

[d4nnyk]

Right I have installed the new diverter valve and all was well for about 5 minutes, then the boiler started making banging and gurgling noises then the pressure went right up and the boiler shut off.

I had to hit the reset button to get going again, then it happened again.
Seems I need a new thermostate the connector has come away from the metal bit that screws into the pipe.

My question is why would this happen, looks like it has melted. I am worried that if I put a new thermostat in it is just going to happen again.

And is the fault I am having noise etc.. be cause my a fault thermostat??

 

[Agile]

I dont know what you mean when you say "thermostat".

the boiler bumping would usually be caused by a heating isolator valve being still closed or a lot of air in the system or a sensor disconnected.

Which problem is it on yours?

Tony

 

[d4nnyk]

Sorry I mean the temperature sensor