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

[Steve2381]

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!

 

[townfanjon]

How old is your boiler steve ?

 

[Steve2381]

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?

 

[townfanjon]

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 .

 

[Steve2381]

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

 

[Gasmk1]

ho wold is the pump and what size 15/50 or 15/60

 

[Steve2381]

Pump... its in the boiler, so no idea. Same age as boiler I assume.
Will lift lid later and look

 

[king of pipes]

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

 

[townfanjon]

Just am idea , whos filter is it ?

 

[Steve2381]

Whose filter? Its a magnaclean underneath the boiler

 

[Rob Foster]

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)

 

[Steve2381]

Is there any chance this flushing is going to make matters worse by moving the crap around the system, or does it properly get rid of all the muck?

 

[king of pipes]

I would say it can only improve it but don't let anyone flush with the boiler connected you most definitely don't want anymore dirt getting in there . Kop

 

[Steve2381]

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.

 

[king of pipes]

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

 

[Rob Foster]

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

 

[Steve2381]

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.

 

[king of pipes]

Why not isolate the boiler drain it and strip out the pump you may find the problem you have the manual guess your is more like this . Kop

 

[Steve2381]

Yea... bit more than that and black.
Nothing like a random fault to spend your time on

 

[ShaunCorbs]

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

??

 

[Rob Foster]

??

I though the pics were he op's system and magnaclean - I didnt read the post properly durrrrrrrr

 

[king of pipes]

Get with the program bud filters are a Worcester (made by adey though they won't admit it ) and a fernox tf1 leak master amazing how much crap they can trap . Cheers kop

I though the pics were he op's system and magnaclean - I didnt read the post properly durrrrrrrr

 

[Steve2381]

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.

 

[king of pipes]

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

 

[Harvest Fields]

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

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.

 

[Rob Foster]

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.

Its always been in my mind to insert a plate heat exchanger right next to the boiler and let it do a tight circuit and let the mucky stuff go around the heating system. The problem has been a heat exchanger which has decent sized pathways thro it and of course two pumps but there is one cause I found it - but its on a computer thats gone lala and is for service - is this a good idea ?

 

[Steve2381]

Changed out the pressure sensor - £23+vat. All working.
Thank you for everyone's advice

 

[Harvest Fields]

Changed out the pressure sensor - £23+vat. All working.
Thank you for everyone's advice

You’re welcome mate