Gran`s mysterious faulty CH

[GranR]

Help! (please) I had a new boiler installed, a Glow worm (Flexicom30hx) and it developed this strange fault - every Monday/Tuesday the boiler does not switch onto its programme and flashes a fault F11. I contacted Glow Worm whose engineer took the front off the boiler, looked at it and says "Nope not the boiler this is your pipes or clock that are at fault". So the guy who installed my Altech Timer came and looked at it and said "Nope no fault here this is the plumbers problem" So the plumber came and said it was maybe a block in one of the pipes as the result of sludge, poured in a cleaning agent and let it run. But still the fault happened, so now he wants to bring some sort of gadget to pressure clean the pipes to clean the blockage, but I keep saying (and apparently no one listens to this Granny!) that if the problem was a blockage in the pipes, surely the system wouldn`t breakdown only on a Monday/Tuesday whilst working perfectly on the other days? I would really value your input to this mystery as I can`t afford to spend money getting these pipes pressure cleaned if the fault is in the clock or the boiler.
Thank you.

 

[Joe 2017]

it could be anything from air in system to sensor

 

[combispecialist]

did he flush system when he fitted boiler???????????

 

[combispecialist]

can be poor circulation issue as well

 

[Joe 2017]

pump could be sticking

 

[darren17]

are you sure it is flashing f11
check it again just to make sure it's not flashing f1

 

[GranR]

are you sure it is flashing f11
check it again just to make sure it's not flashing f1

Its definately flashing F11, and yes we had the pipes flushed out, some of them replaced from where the old boiler was to the position of the new boiler and also all the radiators renewed. I don`t think this problems is caused by air in the pipes, because surely the air would be causing much more intermittant problems and not just on a Monday/Tues?

 

[darren17]

f11 means user interface connection fault.
the chap that came from glow-worm should have checked these boards
the advice is to get an electrician that knows how to do boiler controls

you should ask him to check wiring between mainboard and user interface

 

[tamz]

Whatever the fault is it is electrical. Pipes don't know what day it is

 

[GranR]

Whatever the fault is it is electrical. Pipes don't know what day it is

This is exactly what I thought! But my husband thinks "Oh the plumber must be right". Thanks to everyone for their input, I just hope it eventually gets sorted out as each Monday/Tuesday I dread as I`m frozen, but now I can "see read these comments from the experts"