Potterton Puma 80 combi boiler no hot water or heating

[Newbee2]

Hi,

I'm new to this forum and boilers in general and wondering if someone could help me.

Since yesterday we have had an issue with our boiler. When using the shower the water pressure was really low and no hot water. The boiler made a funny noise and cut out.

We re-lit the pilot light but now whenever you turn on a hot tap or the shower it boosts and the burner kicks in but then cuts out after less than a minute.

We tested the CH and again the burner kicks in and then cuts out in under a minute.

Does anyone know if there's a simple solution or do we need to get someone out?

Thanks.

 

[bellairaphon]

whats the system pressure? you have to look underneath the boiler

Nath.

 

[Newbee2]

Hi Nath,

The red pointer is sitting at just past 2 and the grey pointer is sitting at just past 1.

From other posts that i've seen, etc the min pressure is 1 so I think that the pressure is ok?

 

[ChrisR]

Make sure the auto air vent, at the very top left of the boiler accessible over the top, has it's finger-screwey thing loose. It probably dribbles, so may have been shut.
It might be blocked with scale though . Remove LH side and crack the nut if that's so.

If it's not that, I'd say the boiler's blocked. Not easy to clear if that's the case.
The HW works reasonably well with a dud pump, and the DV would affect CH or HW, not both.

 

[Newbee2]

Hi,

Is the air vent the big pipe coming out of the top going to the outside?!

It has two screws in it, nothing dribbling though.

 

[Newbee2]

Think I've got the air vent - top left with a little black button thing that turns? If so then that all seems fine, the finger screwy thing (little black button) is nice and loose and nothing dribbling.

What's DV?!

 

[bellairaphon]

Have you topped the system pressure up. renowned for airlocks these boilers. like chris said the aav become choked up. when was the boiler last serviced?When the boiler starts is the pump running?

Nath

 

[Newbee2]

Hi Nath,

I haven't done that. The pressure guage seemed to be ok though (red pointer just over 2 and grey pointer just over 1)? Should the red pointer be nearer 3?

If so do you know how I top up the system pressure?

I think the pumps running - it all fires up like normal when you first run a hot tap or turn on the heating and then just cuts out.

Thanks