The dreaded F.9... a question regarding flushing | Plumbing Jobs | The Job-board | Plumbers Forums

Welcome to the forum. Although you can post in any forum, the USA forum is here in case of local regs or laws

The dreaded F.9... a question regarding flushing

Post thread
Post reply

Discuss The dreaded F.9... a question regarding flushing in the Plumbing Jobs | The Job-board area at Plumbers Forums

S

Steve2381

Messages
11
Hello all.
Sparky here... so not totally a newbie in the world of plumbing.

Our Glowworm Flexicom SX (Yea, I know... not amazing but existing) has developed an F9 fault.
Not water pressure. Cleaned out the Mag filter below the boiler, and it was dirty but not horrific.
Had the boiler serviced last week, now its worse. Trips out constantly all day. Sometimes it resets immediately, and sometimes it take 10 attempts.
Plumber quoted £400+vat to flush the system, which I think it desperately needs, as we have some rads (12 in total) that just don't heat no matter what you do (I changed the Thermo rad valves)
Question... does a system flush clear the matrix in the boiler? Wondering if crap in the matrix is causing an issue (said Neo).
£400+vat... sounds expensive? But I understand its a days work, and pipe bursting is possible.
Are there no further diagnostics I can do myself to narrow the search for the F9 error?
We installed a house water softener about a year ago and changed the pressurised cylinder as it was 25% calcium and the hot water kept failing.
Suggestions on a post card please!
 
Last edited:
Hmm.. good question. It was here when we moved in. Last owners didn't install it, and they were here 2 years. So... minimum 3 years, but probably 5+ I would think.
Total lack of dated paperwork associated with it unfortunately

New boiler?
 
Erm a bit drastic changing it on 5 , 7/8 defo change it . But they are not the best , but by no means the worse .
Does sound like a flush is needed , but there could be a few other problems by the sound of it , namely because you have problems with heating and hot water .
 
Well hot water is fine. Since cylinder change (which weighed a ton - v bad water here), its been fine.
Boiler been ok all morning. Seems to be tripped most mornings when I wake up, but water pressure seems totally fine (and plumber said it was more than good enough).
Tried bypassing the Kinetico house water softener just in case that was creating low pressure (grabbing at straws), but no different.
Heating has never been good. Pipework is a bit hap hazard I think.
Dining rad and G/F WC have never got hot since I have been here. Spent a day once trying to balance all the rads, but never achieved it... just moved the heat around the system and gave up in the end.
Hmmmm
 
Dirt in the flow sensor once that dirt gets in there its a pita causing boiler to go to fault . I would disconnect the flow and return and connect the flushing unit direct on to the boiler and flush it through, drain it fit a new flow sensor , the system will be next jet flush that drain it cut a type mesh strainer after the mag filter this may seem overkill but the mag filter won't stop everything and I have done this and it solved the problem . Cheers kop
 
Early magnaclean where not the best but most popular filter on the block - fine particles did pass by and the magnet was weak compared to other ones. Its quite possible to rig up your own flush circuit around the boiler it might even go backwards and forwards.
We used to do it to descale instant water heaters in Bath - Mersey Trent etc loads of rock. To save £400 its worth a punt especially in August - then thro boiler away if its still wreck bang another cheap on in as most new ones only last 3-4 years anyway now (my opinion)
 
Last edited:
OK. Got hold of the manual (thanks Google) and pressed the - button when it tried to fire.
Threw up S 97 state code which is either pressure sensor or pump not running. Tapped the pump with a screwdriver and it fired.
Hmmm.... will wait til it fails again and try tapping the pump once more.
 
Problem will be caused by dirt bud i used to fit and work on these for a company get it cleaned imagine this sort of dirt getting past the filter would play up any boiler. Kop

Screenshot_20180826-181513.png


Screenshot_20180826-181746.png
 
oh dear thats very bad, you really let that go and at that point the magnaclean will be useless - nice pics I will put it in my rogues gallery.
send it to Adey (magnaclean) they will love it. So isolate boiler and flush it. Then isolate system and flush it for a long time backwards and fwds. At this level I expect the rads are badly affected so you will need to go along the bottom with a magnet - use the magnaclean one to break up the sludge compacted. You have black sludge and some brown - brown is more oxidised which means there is leak, black is more anerobic and is a reaction between various metals in the system
 
My filter wasn't anything like that dirty.... just a film of black over the centre piece.
I am starting to lean towards either a sticky pump, or a faulty pressure sensor. Next time it locks out, I am going to see if there is 230v to the pump... and then see if its actually turning.
 
Rob Foster said:
oh dear thats very bad, you really let that go and at that point the magnaclean will be useless - nice pics I will put it in my rogues gallery.
send it to Adey (magnaclean) they will love it. So isolate boiler and flush it. Then isolate system and flush it for a long time backwards and fwds. At this level I expect the rads are badly affected so you will need to go along the bottom with a magnet - use the magnaclean one to break up the sludge compacted. You have black sludge and some brown - brown is more oxidised which means there is leak, black is more anerobic and is a reaction between various metals in the system
Click to expand...

??
 
Just to keep all updated.... still no fix. I ordered a new pressure sensor, as S97 flashes when you ask it to display its current activity, and that can either be a dud/blocked pump or the pressure sensor.
Pump def OK, and sensor only £23.
I assume I isolate the boiler using the valves underneath it and swap it out.
We had the water pressure checked here by the water board... they said it was above average pressure. Nothing stupid like the pressure coming in is too high? I highly doubt it.
 
Drain the boiler after isolation bud protect any electrical parts plenty of blue roll to hand, as has been said before get it cleaned properly first and protected or you will end up back in the same position. Kop
 
king of pipes said:
Drain the boiler after isolation bud protect any electrical parts plenty of blue roll to hand, as has been said before get it cleaned properly first and protected or you will end up back in the same position. Kop
Click to expand...
I got called to a Vaillant the other week where the sensor had blocked. He had the sensor replaced a few weeks before and it was blocked solid again. I am going to flush the system for them in a few weeks. The water way on the sensor is so small on these sensors that it doesn’t take much before they get blocked.
 
New posts
Back
Top