Vaillant Combi Boiler Unvented Cylinder - Hot water problem

[David505]

Hello,
I have a Combi Boiler (Vaillant Ecotec Plus 428) and an Unvented Cylinder (Vaillant uniSTOR VIH GB 180s). Since yesterday we have no more hot water in the house, it comes out cold or luke warm. But the heating works fine.

When a hot water tap is fully opened, the boiler reads S.30 (no heating demand from external source). I have run the diagnostic, and the hot water flow sensor (D.36) reads 0 l/min as well.

My question is could the issue be most likely with the boiler (aqua sensor..) or the cylinder (valve..) ?
I'm wondering if I should call an unvented qualified or a gas engineer.

Thank you for your help.
David.

 

[Alex Knight]

Issue probably with zone valve to cylinder, you need an unvented g3 engineer to fix just use immersion temporarily

 

[Scott_D]

438 or 838

 

[David505]

Thank you for the reply. It is actually the Ecotec Plus 428.
Can I set up the immersion heater manually? I couldnt see a switch on the tank.

 

[David505]

Issue probably with zone valve to cylinder, you need an unvented g3 engineer to fix just use immersion temporarily

Hi Alex,
I've attached a picture of what I believe to be the Zone Valve of my cylinder. I see there's a 'Manual Open' mode.
Would you know how to use it to troubleshoot perhaps?
Thank you,

plumbinn.co.uk/prodimg/80/honeywell-v4073a-zone-valve.jpg

 

[Last Plumber]

Ecotec 428 is not a combi

 

[Last Plumber]

You need a heating engineer

 

[David505]

You need a heating engineer

Ah, you are right, it is a normal boiler, not a combi.

You think I should contact a heating engineer to check the boiler, not a plumber to check the valve of my unvented cylinder?

 

[Scott_D]

Post some actual pictures, thats the wrong sort of valve for an unvented cylinder
Or post your loaction on here, you may need a gas safe registered plumber with unvented (G3) ticket

 

[Scott_D]

Post some actual pictures, thats the wrong sort of valve for an unvented cylinder
Or post your loaction on here, you may need a gas safe registered plumber with unvented (G3) ticket

 

[David505]

Post some actual pictures, thats the wrong sort of valve for an unvented cylinder
Or post your loaction on here, you may need a gas safe registered plumber with unvented (G3) ticket

I've attached a picture of the actual valve.
Thank you,

 

[David505]

I confirm that when the programmer is on (from 6am to 8am) the boiler receives no heat demand (code S.30) so does not ignite.

But later today when I turned on the programmer, the boiler did ignite, I saw the zone valve opening and the pipe to the cylinder getting hot. But just for a couple of minutes, nothing after that.

Is the issue more likely with the programmer or the valve itself (Tower 2port VAL222MV)?





PS: There's hot water when I use the electrical immersion heater.

 

[joni os]

If heating is working, nothing wrong with boiler. G3 qualified needed. Suspect safety cutout on cylinder. Definitely not a DIY. Must not be bypassed.

 

[David505]

If heating is working, nothing wrong with boiler. G3 qualified needed. Suspect safety cutout on cylinder. Definitely not a DIY. Must not be bypassed.

Thanks for your reply. So does the cylinder cutout close the zone valve AND stop the boiler? That would explain why I saw the boiler stopped after few minutes.

I see there is a thermal cutout reset button, but I'll contact a G3 qualified. Thank you.