problem firing up bolier after pipe repair

[shaner500]

hi all a mate of mine has moved in to a house while doing a bit of diy
he put a screw through one of the central heating pipes under floorboards.
so i turned off water at stopcock.
and there was a drain off valve near boiler so i opened that.
then i fixed the section of pipe.
turned water back on etc switched boiler on and it wont fire up.
its a baxi solo 15 he. it appears to be a open vented system.
when boiler is on i get fault lights on
red led lockout on. green boiler light flashing. power light flashing.
on the boiler panel this code.
says no flow.
in the manual it says dry fire.
any ideas what to do.

ive bled radiators and getting no joiy from it.

cheers

[screech]

it's either an air lock or the flow sensor is blocked/stuck

[htg engineer]

Pump running ?

Isolation valves under boiler open ? i've seen people panic when water starts quirting all over and they isolate every valve accessible, also check all radiator valves are open - if they're not the water cannot circulate.

Boiler pressure between 1.0 and 1.5 bar ?


htg

[Peterbirkby]

I know it's an old post but there seems to be no real answers anywhere.

What I did was turn the boiler off, take the front cover off, unplug the flow switch, turn boiler on, (my boiler now sounded like it was filling up) leave it for about 5 mins, it will properly go into lockout again, but just leave it. After it sounds like its carming down, switch the boiler off, connect the flow switch again, the turn the boiler back on.

This seemed to work for me.

I had to do this after I drained the system down to extend some unsightly pipes coming down the middle of the bathroom. (What was the plumber thinking)
After I filled it up the boiler went straight into water flow/ flow return reversed lockout.

The above fixed mine, it might not fix yours, do this completely at your own risk.

[htg engineer]

Unplugging the flow switch doesn't do anything - apart from not giving any fault codes as there's no flow detected.

removing boiler covers and dies-connecting electrical components, safety components in this case. Should only be carried out by a Registered Gas Installer.

[Peterbirkby]

The boiler already had a fault, it locked itself out, and kept the flow sensor & valve closed.
By unplugging it and turning the boiler on, 1 it wasn't going to fire up because all the components wasn't connected, but what it DID do was allow water into the boiler. Once the water sounded like it had stopped running, I reconnected everything and it worked.
Funny how perfectic Swale heating engineers couldn't fix this problem by I could.
I actually wonder how lax the gas safe examination must be if these are the kind of people coming out of colleges nowadays.

[Peterbirkby]

And also htc, whats all the talk about between 1 & 1.5 bar. The boiler in question is a solo 15he oven vented. On open vented systems there is no pressure. Hence the term open vented.