Suanier Dvual not permenant hot water

[Bezad]

I have been asked to look at a Suanier Duval- Thema classic F24E with 3 years old everyrhing is working fine but sometimes hot water get cold.
I checked the domestic heat exchanger it was clean and also the divered valve is working fine I thought the water flow switch ( or water sencer switch) is faulty I change it with a new one it didn't help I talked to suanier Duval technical support after half and hour on hold they advised me to change the pcb and I did change the pcb, unfortuanatly the probelm still there any help will be appreciated.

 

[Slugbabydotcom]

Are you corgi? from what you tell me I assume you are?

Have you checked the gas pressures and water flow rate?

Is it showing any fault codes?

You asked for any help so here's how I would approach it

To get anywhere with this you need to figure out which device is turning off the gas then find out if that part is doing its job correctly or not.

Some likely candidates

Flow switch. Ok you already went through that bit Just check its function and connections

CH thermistor. Normally number one suspect but this is the clip on type which dont go that often. Weak pump, DV which you have checked or crud in one of the heat exchangers. Secondary HE is a highly likely cause.

Overheat stat. Ruled out in this case as it would have to be reset

Flame sensing . Sensor problem, gas pressure prob, Debris on the burner near the sensor, weak fan / flue problems.

APS. Faulty APS and again weak fan / flue problems.

Another thing ... Check the electrical connections. I once got tortured by a boiler with those type of connections on the pcb. [baxi genesis] Make sure all the connections are clean with a squirt of switch cleaner or something.

That should keep you going ... It is 4.40 am, the sun will be up soon and I need to get back in my coffin

 

[Agile]

Is the Sonya Duval tech help still a premium rate number at 50p per minute?

A 30 minute call will have cost you £15 and they have sold a PCB for about £90 which was not required.

Are you sure that you are CORGI registered?

Tony