Ariston Clas HE Evo system issue

[GooseyGoose]

Hi all,

Not sure if you can help me on this one but im pulling my hair out with this. Wondering if any experts on here could pass on some much needed expertise.

So basically my boiler PCB went pop last week. Got another PCB identical to original and swapped over. Since changing the PCB when I try to send DHW or CH, the sensor will click, pump will kick in for 2 secs and then turn back off, like theres resistance in the pipes. The boiler will then fire up, kettle the water and shut down with error code 104 (lack of circulation).

- I removed the bleed screw in pump and checked it was free, it was.
- Vented every radiator and also the manual vent in the boiler for air and its all fine.
- Replaced the pump thinking it could be faulty but same happens.
- Checked all valves are open under boiler.
- Pulled fresh water through the boiler and back out the manual vent to check for a blockage.

Literally struggling to think what else it could be. Would a faulty Auto Air Valve cause a restriction issue possibly? Definitely feels like theres a flow restriction somewhere but I just casnt figure out where.

Thanks for the help!

 

[ianmcd]

Why did you change the PCB ? what was the fault ? what controls do you have ? is it S plan Y plan or what ?

 

[GooseyGoose]

The PCB blew because my partner managed to get some water on it. The 2a rapid fuse blew and would constantly blow as soon as power was put to it afterwards. Pretty sure it was knackered.

Its an S plan system. I checked the diverter valve motor just now also and can feel the motor turning so that seems to be fine also.

Thanks

 

[ianmcd]

The PCB blew because my partner managed to get some water on it. The 2a rapid fuse blew and would constantly blow as soon as power was put to it afterwards. Pretty sure it was knackered.

Its an S plan system. I checked the diverter valve motor just now also and can feel the motor turning so that seems to be fine also.

Thanks

If it is an S plan you have two divereter valves, as you call them , but they are motorised zone valves they dont divert anything

 

[ianmcd]

Post a pic of your "divereter" valve I am betting you have a Y plan

 

[CBW]

Hi Got another PCB identical to original and swapped over.

So not a genuine one?

 

[GooseyGoose]

Post a pic of your "divereter" valve I am betting you have a Y plan

Apologies I meant to write Y plan. Yes

 

[GooseyGoose]

So not a genuine one?

Yep genuine part buddy

 

[ianmcd]

The 3 port valve is faulty, the little burst is normal when switching between demands , but one of the microswitches have failed

 

[GooseyGoose]

The 3 port valve is faulty, the little burst is normal when switching between demands , but one of the microswitches have failed

Legend. Is there a way to test its faulty by any chance?

 

[ianmcd]

if you have a multi meter , with a call for CH and HW and stats also demanding, you should have 230V AC on the orange wire from the mid position valve , if it is indeed a faulty valve you can if you want connect the orange wire to the CH on live and manually latch the valve in the manual position till you can get a new one, you will be over riding the controls though so will have to manually switch it on and off, but will give you heating and HW till you can get it sorted

 

[GooseyGoose]

if you have a multi meter , with a call for CH and HW and stats also demanding, you should have 230V AC on the orange wire from the mid position valve , if it is indeed a faulty valve you can if you want connect the orange wire to the CH on live and manually latch the valve in the manual position till you can get a new one, you will be over riding the controls though so will have to manually switch it on and off, but will give you heating and HW till you can get it sorted

I'm working till later on tonight but will jump on it tomorrow morning and let you know my findings. I assumed it was a valve, but couldn't get my head around which one thanks so much mate.

 

[Datsunadz]

I'm working till later on tonight but will jump on it tomorrow morning and let you know my findings. I assumed it was a valve, but couldn't get my head around which one thanks so much mate.

Did the diverter valve sort your issue Goose? I have the exact same symptoms.

British Gas replaced the pump and the secondary heat exchanger in 3 separate visits. The pump stopped it for a while but after a couple of months it came back. They changed the exchanger yesterday and its doing error 104 again today.

If I take the diverter valve off and power the boiler on I can see the plunger coming out and it's solid (You can't press it in, then it goes back in on its own). It doesn't seem to move when I call for heat at all.

 

[ianmcd]

Did the diverter valve sort your issue Goose? I have the exact same symptoms.

British Gas replaced the pump and the secondary heat exchanger in 3 separate visits. The pump stopped it for a while but after a couple of months it came back. They changed the exchanger yesterday and its doing error 104 again today.

If I take the diverter valve off and power the boiler on I can see the plunger coming out and it's solid (You can't press it in, then it goes back in on its own). It doesn't seem to move when I call for heat at all.

different boiler and system to what you have yours is a combi boiler