Valliant AquaPlus VUI 362-7 Help!

[ianmcd]

Sorry I am totally confused with what you are saying so I will go through how your boiler works, cold feed is simply that the cold water goes into the plate heat exchanger and comes out of the tap hot, the water inside your radiators and inside the boiler is a sealed system and the pressure is measured by the pressure gauge on the front of the boiler, you top up this pressure and then close the valves and leave , the silver hose must be connected to fill the boiler and can be disconnected afterwards, the boiler has a Pressure relief valve that is set to operate if the pressure exceeds 3 Bar, this vents the water to outside to protect the boiler, you should not have any water coming out of the PRV outlet under normal working conditions

 

[ADurr]

Sorry I am totally confused with what you are saying so I will go through how your boiler works, cold feed is simply that the cold water goes into the plate heat exchanger and comes out of the tap hot, the water inside your radiators and inside the boiler is a sealed system and the pressure is measured by the pressure gauge on the front of the boiler, you top up this pressure and then close the valves and leave , the silver hose must be connected to fill the boiler and can be disconnected afterwards, the boiler has a Pressure relief valve that is set to operate if the pressure exceeds 3 Bar, this vents the water to outside to protect the boiler, you should not have any water coming out of the PRV outlet under normal working conditions

ok understand.

so following the steps you said before to test if the filling loop valves we’re passing the answer is? I assume the dribble every 7 seconds is due to the PRV?

the issue that needed addressing in my original post was the constant water being dumped outside when the boiler was on, I assume this is now down to the PRV? So the PRV needs replacing?

 

[ADurr]

@ianmcd

maybe worth explaining my original symptoms better.

with cold feed on, open filling loop and fill to green section roughly 1.5bar. Close filling loop.

normal boiler operation, hot water, CH etc.

water is trickling from the outside overflow constantly, and pressure on gauge rising into the red.

I want to stop the water outside and stabilise the pressure.

questions:

1) are my symptoms all down to the PRV?
2) are my filling loop valves OK after performing the tests you said? Ie they are not passing?
3) what else should I check before getting the PRV replaced.

thanks!

 

[ianmcd]

So the PRV needs replacing?

Possibly , but it is designed to operate at 3 Bar, you say your gauge is not registering any pressure , if it is blocked and you are putting more than 3 Bar in then the PRV is just doing its job

 

[ADurr]

Possibly , but it is designed to operate at 3 Bar, you say your gauge is not registering any pressure , if it is blocked and you are putting more than 3 Bar in then the PRV is just doing its job

sorry double posted whilst you were responding. Not sure where to go now but maybe my new post will help explain...

 

[ianmcd]

Your expansion vessel needs recharging/replacing and probably a new PRV now too

 

[ADurr]

How can I recharge the vessel to check that before I buy replacement and also PRV?

 

[ADurr]

How can I recharge the vessel to check that before I buy replacement and also PRV?

 

[ianmcd]

Look at the FAQs there are hundreds of posts explaining how to do it, follow All the steps you can not cut corners it has to be done properly

 

[ADurr]

Look at the FAQs there are hundreds of posts explaining how to do it, follow All the steps you can not cut corners it has to be done properly

Thanks @ianmcd

found the faq.

which is my best place to drain off the system as to get the right pressure in the vessel?

 

[ianmcd]

Use this drain attach a hose into a bucket and open the drain valve, when water stops attach a pump to the EV and start pumping lots more water will come out, when the water stops coming out keep pumping till about 1 Bar pressure in EV, remove pump close drain and re-pressurise water side of your boiler.

 

[ADurr]

Use this drain attach a hose into a bucket and open the drain valve, when water stops attach a pump to the EV and start pumping lots more water will come out, when the water stops coming out keep pumping till about 1 Bar pressure in EV, remove pump close drain and re-pressurise water side of your boiler.

Thanks Ian.

So I’ve drained the expansion vessel, must have been 8litres in there, repressurised to 1bar and filled the cold loop to 1.5bar on the control unit gauge. Boiler back on and ran the hot tap. Pressure looks stable so far holding in the green at 1.5bar.

overflow pipe outside is still letting a little water - what else could now be causing this? The vessel is holding 1 bar, so I assume it’s only the PRV that maybe passing a little?

thanks for your help.

 

[ianmcd]

yes with a flat expansion vessel the PRV can be cruded up, it is possible to clean them, I do it all the time but they are not expensive so maybe best if you get a new one

 

[ADurr]

yes with a flat expansion vessel the PRV can be cruded up, it is possible to clean them, I do it all the time but they are not expensive so maybe best if you get a new one

Awesome thanks I’ll sort a new one and replace it if that’ll be the culprit for the leaking overflow

 

[ADurr]

Awesome thanks I’ll sort a new one and replace it if that’ll be the culprit for the leaking overflow

is the procedure similar to drain the boiler like I did for the PV and then just replace the unit? Assume it’s just this I need?