3 port valve problem ??

[Sheldont79]

Good evening...
I have a problem with my system and wonder if you could help ?

I have a system boiler installed relitvy new boiler showing no error codes.

When i click hot water on postion on the electronic pad underneath the boiler doesnt fire up to turn the hot water on.

it stays idle.

There are no problems when i switch the heating on , it fires up and all the radiators work as they shud do.

Whilst the heating is on i click the hot water on and the boiler then shuts down back to idle mode.

As soon as i switch the hot water off then the boiler comes back on for the central heating.
The arm on the motor isnt loose it has to be forced back too be locked into the barb... then when i click the hot water on the electronic pad it winds back to the auto position

Any ideas / advice you could please help me with ?? from what iv read it could be a faulty 3 port valve but oviously i need to get someone out to find where the problem is just looking for advice so i know what im on about when gettin someone here


I can get hot water by using the seperate electrical switch to heat the water and iv opened the valve to manual on the 3 port valve for when the heatings on.

Many thanks

 

[cross thread]

what setting is the cylinder stat set at ? located on the hot water cylinder

 

[stem]

The three port valve when it isn't energised sits at the hot water position, so if it was faulty it would be there anyway, so I don't think it's likely to be faulty. The hot water cylinder thermostat is what is responsible for firing the boiler when hot water is required. But this sounds like it may be a wiring fault to me. Was it working OK previously or has anything been changed at the time of the fault appearing?

 

[Sheldont79]

Thanks for replies.

Its been working fine no probs at all until this.

Il check what its set at at report bk

 

[stem]

Thanks for the update, I just wanted to check. Sometimes we get questions on here regarding faults that have been caused by the OP but they fail to mention that they have just replaced something.

So, it sounds like a faulty cylinder thermostat to me. The Cylinder thermostat is responsible for operating the boiler under two conditions:

1. When Hot water only is required
2. When Hot water and central heating are required

In both of these circumstances you say your boiler doesn't work.

On the other hand, when only central heating is required the motorised valve is responsible for operating the boiler, and in this case yours does work.

If you are electrically competent, it's not difficult to test your cylinder thermostat and I can tell you how, but you will need to provide details of it (make / model)

 

[Sheldont79]

Thanks much appreciated.
When the hw only the boiler doesnt fire light is on the programmer tho bit boiler doesnt respond.
When ch only its fine all rads work... if i press hw when ch is on the boiler shuts down and goes into idle mode ...no error codes.

The hw works fine when i use the emersion electrical switch ( just gota remember to turn it off )

I will get the make/ model number when i get home.
Thanks again for taking the time to reply.

 

[stem]

That does look like the cylinder thermostat.

The immersion heater isn't connected in any way to your boiler / heating. It's just a simple electric heating element inside the hot water cylinder that heats it up like a giant kettle. At least you can get hot water by using it, but it will cost you about 3 times as much to run compared to gas.

 

[Sheldont79]

Yes i realise the cost is more hence the reason im looking at gettin it sorted asap.

I leave the valve open when ch is on to get hw that way too.

Thanks again

 

[Sheldont79]

Its a range model codice.....
But i may of had a bit of a result
There was a black button cover... i removed this to reveal a reset button... i reset it...
I put hw on and boiler fired up... i turned it off put ch on boiler fired up... so i put hw on whilst heating was on and it didnt shut boiler down
Im goin to see how it goes next day or so.
Thankyou for taking the time to reply to me its only because you said it was the thermostat that i looked at this so thankyou

 

[stem]

Excellent, & well done for asking before replacing the motorised valve first, it usually gets the blame.

It is the high limit thermostat that has tripped so the cylinder has probably overheated, if it happens again it's possible the thermostat is faulty and not controlling the temperature properly, if it does, try turning the thermostat down slightly, and don't use the immersion.

 

[Sheldont79]

Thanks stem really appreciate your guidance on this.

I dont use the imersion as a rule anyways ... fingers crossed its now resolved but like u say if it does it again theres an ovious fault

All the best