Vaillant 428 - no heating or hot water

[krazaq]

A new problem. Vaillant 428 installed on y plan.

When hot water is on, the radiators were getting hot. so i thought this is cos the rad return feed is connected to the boiler return from hot water tank.

So i thought i would install a one way valve on the radiator return.

Now the water was switched on and it heated to the necessary 60 deg as per the cylinder stat. now heaters have been turned on nothing is happpening.

Water in the boiler when the pump is on is way too hot for the boiler to stay on.


What can i do to fix this problem?

 

[Youllneverguess]

Did you check to see if the heating return was warming up rather than the flow?

Could be plumbed incorrectly.

Could still have a wiring fault.

 

[krazaq]

ok now closed the bathroom radiator return valve and its working ok. everything works on the electronic side, nice and neat.

there is definatly a plumbing issue. all the heaters in the house are warming up nicely and everything is working as it should except the bathroom radiator. if i open the valve the whole system shuts down.

What can it be? any ideas?

 

[Youllneverguess]

You said on another thread that it is a large system, so I am a little surprised that one towel rail can disturb the whole system.

Has the ch been properly balanced?

Is the towel rail plumbing across the primaries? Does it work in hot water only mode if you turn it back on?

 

[krazaq]

hi yes big house hence the boiler. if i turn it on, the heating will go off but the water will work and the boiler will switch on and off to keep the water at the set temp. so i don't understand it.

but no heating downstairs, but majority of heaters upstairs will be hot even if the programmer is not calling for heating.

 

[Youllneverguess]

Sounds like a plumbing disaster.

 

[sooey]

Sounds like joe90 fitted it.

 

[krazaq]

this is what i told my wife and she told me he is a plumber and knows whats he's doing....i will try and call him back tomorrow and see what he's got to say and let you guys know. i get the feeling he is going to blame the electrics.

 

[Youllneverguess]

Laughing at Sooey not you ...


Get him back.

the electrics can be proved by watching the valve motion with the cover off. IF that is doing the correct thing then don't be fobbed off.

Here is the rest of the document I posted the other day:

Untitled

• Youllneverguess
• 10 Sep 2011
• 1

 

[krazaq]

yes i have checked the valve and its perfect to the letter. there has to be something with plumbing under the bathroom towel rail. i was hoping he would not need to rip it up again but i think he may just have to.

 

[dreadnoughtheating]

The 428 needs 28mm Flow & Returns, also a 'y' plan motorised valve may restrict flow further (the waterways are small). I always put these on an 's' plan with 28mm two port valves to alleviate circulation issues.

Hope this helps.

DH