Grant 90 boiler leaking...HELP!

[mrbriggs]

Hi all,

Another problem with the boiler. It is leaking from a valve near the top front left, located just behind where the timer is, on the main tank.

It has a twist off valve similar to a tyre valve, but it appears to be leaking from the valve itself. The valve is not attached to anything, it just bolts on to the tank, so I presume it's some kind of breather pipe/valve? Could it be the auto air vent? Does anyone know what it is?

I got in yesterday from work and I could hear a hissing, and it was coming from there, and also noticed that the pressure had dropped to almost 0.

Any help would be appreciated

Lee.

 

[jackthom]

If it's identical to a car tyre valve it sounds like the Expansion Vessel pressurisation valve.

If it is and water is coming out of it, that's a problem because there should only be air in the compartment.

 

[ajstoneservices]

System boiler? sounds like the auto air vent leaking it may be marked 10bar 115c. If its on the red vessel behind the front cover then it is the expansion vessel.

 

[mrbriggs]

No, it's not the expansion tank, as I replaced that last year (was leaking water as the seal inside had split)

This is a pipe that is attached to the tank behind the control panel, so when you open the front door, it is top left.

Does anyone have a diagram of the boiler, or a list of spare parts for it? If I had a pic, I could show you. I'm pretty certain that if I get this part replaced, it would solve everything. I jsut don't know what the part is!!!! argghhhhhhh!!!

 

[oilman]

You tell us exactly what model boiler it is and we might be able to help. my guess it is an auto-air vent, but your description does not suggest that.

 

[ajstoneservices]

View media item 6955



Can you see the part in this photo's

 

[mrbriggs]

All I know is it's a Grant 90.

If it is an auto air vent, the only thing I can think of is they have modified the part so it looks different now. What is in there now is a straight pipe about 2 inches tall, which bolts on to the tank and the other end has a screw on cap and a tyre valve (similar) which screws on top of that.

 

[oilman]

In which case it could be a manual vent.

 

[mrbriggs]

Where would I get a replacement?

 

[oilman]

Grant do a combi 90, a Euroflame 90 a Multipass 90, a Vortex 90, you havent posted a picture and you say it could be a modified part.


I use one of these

 

[mrbriggs]

hahaha, I will get a picture when I get home.

 

[mrbriggs]

OK, it's a combi 90. I have attached a pic of the offending item. It looks like it has corroded through some of the insualtion around the outside of the tank.

Untitled

• mrbriggs
• 17 Dec 2008
• 1

 

[AlanE]

Looks like an automatic air vent.

 

[Agile]

OK its an auto air vent.

But the whole thing looks in such poor condition that you could always treat yourself to a nice new boiler for Christmas!

Tony

 

[oilman]

That's a standard part, available on line or from plumbers' merchants. Can't tell whether it's 3/8 BSP or 1/2 BSP. Replacements are available with a self sealing valve so when you replace it next time it's easier.

look here for air vents part 7703 and 7704. They're so cheap, get one of each size.