High Boiiler Pressure

[fadsarmy]

Hi everyone. I have a Vailant turbomax plus 837e boiler. Just checked the pressure and noticed it was just under 3 but is working fine. It was 1.5 when I checked a couple of weeks ago. Is it something I could attempt to sort out or do I need to call out an engineer. Also, is it safe to continue using?

 

[Scott_D]

Bleed some water out from a rad air vent or drain off

Disconnect the filling loop as it could be passing

 

[Darren Jackson]

I Agree with scott_d. Drain some water out & make sure the filling loop is not passing by turning the valves to it fully off and then take off the connecting hose. put an 1/2" female cap on the end of each valve. If the pressure still creeps up then you will need an engineer to check the expansion vessel, amongst other things.

 

[fadsarmy]

Thanks for the reply guys. There's no filling loop just a valve which you turn with a screwdriver.

 

[rpm]

Have a look for a braided flexi hose with valves and handles each end, they are not always close to the boiler.

 

[Darren Jackson]

Locate the filling valve handle on the cold water inlet
filling valve under the boiler & make sure it is fully off. Then you have to remove the filling valve handle and locate on return filling
valve and turn that one fully off as well. There is a flexible filling loop on these boilers its just hidden. Once you're happy they are both turned off properly then remove valve handle and refit on cold water inlet. and take off the connecting hose and cap open ends.

 

[Darren Jackson]

Sorry forgot to mention you have to take off the lower cover plate underneath the boiler to access the built in filling loop. It can be safely removed by you simply unscrewing it without compromising the boilers safety or breaking any seals.

 

[fixitflav]

There is a flexible filling loop on these boilers its just hidden.

My son had a new combi a couple of years back and I'm pretty sure there is no flexible, just rigid pipe with a valve each end.
Can't remember whether it's a Vaillant.
I think the valve on the mains supply is 3-port, so in the Fill position flow to the heat exchanger for HW is stopped, to avoid a problem of somebody turning a hot tap on when you're trying to fill. The ones I've seen with a flexi don't have that feature, each valve is on a tee.

 

[Harvest Fields]

The filling loop is built in on yours mate. I believe.

 

[Harvest Fields]

The filling loop is built in on yours mate. I believe.

There should be a hole in the centre of the slot where you are using the screwdriver on. Use an alum key and make sure it is fully in the off position.

 

[fadsarmy]

There should be a hole in the centre of the slot where you are using the screwdriver on. Use an alum key and make sure it is fully in the off position.

Thanks. How do I know the off position? When I turn it either way there's no sound of water movement like there was previously.

 

[Harvest Fields]

Or does it look like this?

 

[Harvest Fields]

If it looks like above there should be x 2 of them (If I remember correctly) but I have been wrong in the past

 

[fadsarmy]

Or does it look like this?

View attachment 33956

Indeed it does.

 

[Harvest Fields]

A radiator bleed kit should fit over the square bit. Should make it easier to turn

 

[Martyn2]

Anyone considered his expansion vessel has gone kaput?

 

[dan_the_plumber]

Yes the filling loop could be passing, but as long as it’s in the off position, I’d say it’s more likely that the expansion vessel needs re-pressurising.