Vaillant ecoTec plus 615 shows High pressure (after holidays switch off)

[grumpypj]

All,

Need your help. We were out of UK for a week and switched the boiler as well as the controller (honeywell electric unit) off. When we got back, I switched on the boiler and all seemed fine. There was hot water within no time. This was mid-night of 20th April. Heating wasn't needed so didn't bother with it. I now realise that the shut down procedure was perhaps not complete.

About 36 hours later of this 'switch-on', the water wasnt hot. I saw that pressure was too high (2.8) & temperature was showing 31 degrees. Using the controller I switched off hot water and pressure dropped to 2.3 bars in 20 minutes. I googled this problem. Tried to drain the radiators (drained about a cup worth water from 3 out of the 5 radiators). This didnt help getting the pressure down. so i didnt drain the other two radiators.

I then turned hot water off and monitored for next 3 hours. Boiler showed 2.3 bars and temperature showed 35 degrees. so without any demand for hot water or boiler, the pressure still didnt go down.

Are there any DIY steps I can do to resolve this on my own before calling a heating engineer?

Enclosed is an image of the pipe work underneath the boiler.

 

[ianmcd]

That black filter with magna tec on it, place a basin or something under it, remove the cap on the bottom and that cap will fit the valve , gently open it untill your pressure is about 1.5 Bar when cold , the close the valve refit the cap and monitor what happens with the pressure , a small increase when hot is normal .

 

[grumpypj]

Thanks for the reply ianmcd

I am an absolute novice so confirming something first. in attached picture ive highlighted my understanding of whats the 'cap' and the 'valve'. Is my understanding correct?

 

[grumpypj]

Ok, spent sometime. I think I know what the cap at the bottom is. The metal thing, I was able to just bring it out by rotating it.
The valve-at the top is another metallic round thing. You were suggesting using the cap as a grip on moving the valve right?

That cap doesn't fit that valve unfortunately.

 

[dilalio]

The cap on the bottom unscrews and is retained from dropping by the rubber band. With the cap removed and dangling you use it as a handle to open the valve which releases water out of the outlet you unscrewed the cap from. The post that the band hangs down from is the spindle of the valve that you open.

 

[dilalio]

Forget the band- you don't have one! But use the cap on that metal spindle which has the black plastic around it - this acts as a tap which opens the outlet valve (all at the bottom of the filter - nothing to do with the top valve.)

When you have drained water out of the system and reduced the pressure then check that your filling loop isn't letting by and adding water to the system. Legally, it should be removed when not in use - this will tell you if the isolator is passing.

 

[grumpypj]

The metal spindle with black plastic, can be moved with a flat screw driver from what I can see.
So i remove the cap and expose the outlet and then use screwdriver to turn the "spindle with plastic".

 

[grumpypj]

I tried that, let out about half a cup of water through that valve. Pressure dropped with just that volume. I wasn't sure how much to let pressure drop.

So I stopped, got valve to original position, placed cap back and started hot water

Like dilalio said- pressure did go up and now it's heating at 2.0 bar. Is even this too high? Should I let some more out?
Also are there any other steps to follow?

 

[dilalio]

2 bar is fine. If it's get to 3 or over then the pressure release valve will discharge and you will hear it release water - that's why you need to check your filling loop.

Pressure should be around 1.2bar on the gauge - when the system is 'cold'

 

[grumpypj]

Ok, got the cold pressure down to 1.1

Fired up heating with target flow temp of 65. Heating nicely with pressure at 1.7b.

I will wait a little and then fire heating up as well and see if pressure fluctuates then. thanks for the help dilalio.

 

[grumpypj]

Dilalio
Is there any reason for boiler to become noisier after doing this? There is a whirring sound from what was a very silent boiler

The pressure is within limits and hot water is flowing ok, no alerts or fault codes are seen. I'm worried I've messed something up now

 

[dilalio]

Top it up with a bit more water - it can go up to 3 bar when hot, before discharging. You might also have air in the boiler from when you dropped the water out, if so, it'll need bleeding out.
But add a little pressure first.

 

[Steelmasons]

Dilalio
Is there any reason for boiler to become noisier after doing this? There is a whirring sound from what was a very silent boiler

The pressure is within limits and hot water is flowing ok, no alerts or fault codes are seen. I'm worried I've messed something up now

What gauge are you reading.

 

[Steelmasons]

Expansion vessel requires pre-charging.

 

[grumpypj]

The pressure bar was being read from the display. On double clicking one of the buttons , flow temperature and pressure bars are displyed. When I let the water out, I monitored that and the inverted triangle bar on the right