Ideal Logic Combi - no water flow lockout

[SJRSJR]

Hi

Before I get the professionals in, I'm wondering if there's anything I've done which caused the problem with my boiler. It's an Ideal Logic Combi 35, installed by the previous owners 2 years ago.

We are redecorating the living room so decamped to the room next door. I closed the TRV on one radiator and opened up the one next door. All seemed fine. Next day we turned the heating on in the afternoon and it wasn't warming up. The was an error on the boiler 'L3 - No Water Flow Lockout'. What does this mean?

I have been able to reset it and we are getting hot water but no central heating. I'm also getting the letter 'c' on the boiler which means Central Heating Demand is on, but nothing's coming through.

Earlier L3 appeared again but I've reset it and it's back to 'c'. The boiler has been fine for 18 months, save for low water pressure occasionally, which had occurred that morning. Pressure gauge is fine now. There is no room thermostat, we switch it on and off at the boiler.

I have googled and found this:
//www.diynot.com/forums/viewtopic.php?p=1932747#1932747

To be honest, I still don't know what it means, so would appreciate any help in the most basic of layman's speak!

Ideal Logic want mega bucks to come out. Is it something any heating engineer could sort? Thanks!

 

[gigz]

Check both F&R valves are open under the boiler. Its the extreme left and right ones. My bet is when its been topped up one of these has been closed by mistake.

 

[SJRSJR]

The CH return is open but I'm not sure about this. I think it's correct as when I've changed it it's prompted error message 'FA' and I've had to reset it. To get the right orientation tilt your head to the left with the screws at the top of the picture.
View media item 72791
The flow pipe is hot from the boiler to the floor but it disappears after that. The return pipe is cold. Does that suggest an airlock? Thanks

 

[gigz]

That valve is closed, point it up and down. Also no fault FA, you sure its not F4 (thermistor fault)

 

[SJRSJR]

Just tried it and got FA again. It's definitely FA. It's as if it's trying but failing to fire up, but the DW fires up ok

 

[SJRSJR]

Just called Ideal. She said immediately FA means that it's a problem with the installation in that the flow and return pipes had been crossed over and even though it's worked since installation, it was eventually going to fail. Does that make sense?

 

[gigz]

I've only ever come across a FA fault on a heat only boiler so its a new one on me. Did you open that valve ? FA on a heat only is where the return pipe is hotter than the flow so the boiler knows its piped up wrong. If yours has been working its piped ok (unless someones been altering things)

 

[SJRSJR]

Yes I opened it but still got the FA fault message. So I switched the lot of and put the kettle on while I started searching about swapped pipes. I just switched it back on and bingo, it seems to be warming up! If the flow pipe is warmed up faster than the return pipe am I right in thinking that the pipework is in order?

One of the kids had a go at topping up the water pressure and must have closed that valve in error.

Thanks very much, you've saved me £300 quid!

 

[gigz]

I'll send you my bill

 

[SJRSJR]

I could offer you a child to sweep your chimney.

 

[Brian Tack]

I have the same problem with this model heat only. I have another thread going on it and everyone has been really helpful. Unfortunately it's still not solved. the return pipe on the boiler gets hotter than the flow.