Pressure gauge not working on Vaillant ecotec pro 28

[Mickrick]

We had a problem yesterday where we had no heating or hot water, although we had around 153m2 of gas on the meter. When I checked the boiler, a 2 and a half year old Vaillant ecotec pro 28, the red light was on and the pressure gauge was right at the bottom. So I connected the priming hose and turned on both valves and nothing happned, the needle was just stuck at the bottom. But then when I tried the heating again, it came on and both it and the hot water worked fine. Then this morning we had no heat or hot water again and I had to go through the same routine again. When I try priming the system, the needle doesn't even flicker.

I haven't got the manual. Can anyone point me in the right direction of what I should be looking at to fix this?

 

[Gas2Air]

You have a leak.

 

[gigz]

Press the minus button on the display, this will give you a readout of the pressure. It should be 1.2 bar. Your gauge could be broke.

 

[Mickrick]

You have a leak.

Yeah that's what I thought at first. But we would have clear evidence of water damage if that were the case as it would have to be a pretty big leak to reduce the pressure to zero and keep it there while it was being repressurised.

Press the minus button on the display, this will give you a readout of the pressure. It should be 1.2 bar. Your gauge could be broke.

I'll do that and let you know what it says. My brother, who is a gas installer but didn't do our installation, says that it may be dirt blocking the pressure sensor. But looking at some of the comments I've seen about Vaillant boilers, it's more likely to be a broken gauge.

 

[Mickrick]

Sorry about replying so late. I checked the pressure and it's reading 0.3 bar and this doesn't change when the priming valve is turned on. But, strangely, when I turn the valve off at the water side first and disconnect the hose, no water comes out. So where is the water going?

 

[swbjackson]

You have a leak.

 

[gigz]

Are you sure the filling loops working. Connect braided hose to cold mains and open it into a dish. If this works it could be the NRV on the loop thats goosed. You NEED to top it up to 1.2 bar and bleed your rads before using your heating/hot water or you could damage the boiler. P.S. You could also have a leak.

 

[Mickrick]

Are you sure the filling loops working. Connect braided hose to cold mains and open it into a dish. If this works it could be the NRV on the loop thats goosed. You NEED to top it up to 1.2 bar and bleed your rads before using your heating/hot water or you could damage the boiler. P.S. You could also have a leak.

Something is definitely wrong and if we do have a leak, it's going to be somewhere difficult to find. Luckily I come from a family with a history of plumbers and heating engineers but my brother is the only one with gas certification. He's going to take a run over sometime today to have a look.

Thanks everyone. I'll let you know the outcome.

 

[HERTS P&D]

A family full of plumbers and you come on here first!



Andy

 

[Mickrick]

A family full of plumbers and you come on here first!



Andy

I know . But as I said, my brother didn't install this system. I don't like getting family to do big jobs for me, too many rows and fallouts when things go bad.

I wanted to see if it was something simple that I could fix myself without having to get someone to have a look. Hey, it is a diy site after all

 

[gigz]

Let us know the outcome

 

[Mickrick]

Okay, so my bro came over, went to the boiler and... the pressure was 2.4 and the needle on the gauge was at midway on the grey. I was gobsmacked to say the least.

We got up today to a freezing cold house, no hot water for the kids to get ready for school or my wife to get ready for work, and the pressure right down again to 0.3, the needle right down at the very bottom, a red light on the far left and F22 flashing on the display.

So one emergency phone call later and my brother is on his way.

I'll let you know how it goes again.

 

[Mickrick]

Sorted. It turns out the non-return valve wasn't working. New one fitted in about 15 minutes and pressure back to normal.