nav[aria-label="Primary Navigation"] { padding: 0; & ul { list-style: none; width: 100%; display: flex; flex-direction: row; justify-content: start; align-items: start; gap: 30px; padding: 0; & li { margin: 0; } & ul li { list-style: none; } } }

Child Item

Boiler doesn't work with error F9 in some mornings

Seregwethrin

Hi,

Boiler is not working in the mornings and going to F9 error mode.

After topping up to 1.4 bar it started to work.

Here's a video how it F9s and tries to work but doesn't at 1.2 bar.
https://www.youtube.com/watch?v=w5WTuTsxPYo
It turns to F9 at the end of the video again.

Do you think I am having leaks somewhere because I topped it up just a few days ago?
1.2 bar should still be okay though, isn't it... I don't understand why I am getting F9 with that.

Any ideas about the fault? Boiler or pipes issue?

I actually think this is happening mostly on cold mornings. Just went outside and I felt like I am in fridge's freezer.

Thank you

Find more posts tagged with

Quick Links

Comments

K.Flyer

Seregwethrin wrote: »

He told me I'd know the pressure is low if the top of the radiators are cold.

That's genius!
If the downstairs radiators are going cold due to lack of water and the boiler is higher than the rads, I'd imagine that the pump is struggling for water as well.

Seregwethrin wrote: »

I am not comfortable without it too. I am sure there is a need for it as the manufacturers installed inside the boiler.

Yep, to warn you of low pressure in the system and protect the boiler components. Just a pity that the Glowworm pressure switch is not a good quality item.

Seregwethrin wrote: »

Though, he really sounded like I don't need it :pac:

It'll be grand so :rolleyes:

Seregwethrin

K.Flyer wrote: »

It will, but how will you now know when you have too little water in the system and the circulation pump is starting to get damaged from running dry?
Unless you have a constant low pressure feed of water this is the risk you take by disabling the pressure switch.
There is a huge difference in cost between replacing the circulation pump against the cost of replacing the pressure switch. In the time it took him to go through changing the settings he would have nearly finished changing the pressure switch.

He told me I'd know the pressure is low if the top of the radiators are cold.

I am not comfortable without it too. I am sure there is a need for it as the manufacturers installed inside the boiler.

I will clean the system first then ask him to install one. Though, he really sounded like I don't need it :pac:

K.Flyer

It will, but how will you now know when you have too little water in the system and the circulation pump is starting to get damaged from running dry?
Unless you have a constant low pressure feed of water this is the risk you take by disabling the pressure switch.
There is a huge difference in cost between replacing the circulation pump against the cost of replacing the pressure switch. In the time it took him to go through changing the settings he would have nearly finished changing the pressure switch.

Seregwethrin

I finally got in the good & quick plumber who serviced my boiler last summer.

His solution was same as @Damien360 and he simply deactivated the boiler's pressure sensor (he called it pressure switch is broken not the sensor, dunno if they separate).

He also told me I don't need the pressure sensor and the boiler can work even at 0 pressure :pac:

I got a Sentinel X400 from Screwfix, I think equivalent of MC5.
I will clean the system now.

I also saw there is Sentinel X200 for boiler noise and then I will inhibit with X100.
Hopefully they will help with the banging sound pipes are making.

John.G

Damien360 wrote: »

I’m not sure that the fault is actually low pressure or failure to see a pressure differential when the pump starts. For whatever reason, a higher pressure will allow the system see the slight increase in pressure when the pump starts before the boiler tries to ignite. So as the pressure sensor blocks more, you need more pressure on system to see the differential.

I do know that it is recommended on sealed systems that the EV is installed on the pump suction and as close to it as possible, the idea is that the pump suction will always be at the EV pressure and the pump discharge at the EV pressure+the pump head, this gives a higher average system pressure which helps to prevent air ingress where there are high system losses. So assuming a EV pressure of 1.5 bar then with the pump off the pump discharge pressure will also be 1.5 bar, as soon as the pump starts, the pump discharge will be 1.8 bar (assuming a pump head of 3M) so the pressure switch, if positioned here will detect this. It would be interesting to see where the pressure switch and EV connections are installed on these boilers or/and to see if there is a momentary jump in the boiler pressure when the pump starts. If the EV is installed at the pump discharge then the pump suction will be the EV pressure-the pump head and the discharge at the EV pressure, again interesting to see what change, if any, when the pump starts.

K.Flyer

Seregwethrin wrote: »

I see, so the process is more complicated than "just some pressure in system at any time"

Thank you

Yes, just because there is pressure in the system it doesn't mean everything is ok in that dept.

Seregwethrin

Damien360 wrote: »

I’m not sure that the fault is actually low pressure or failure to see a pressure differential when the pump starts. For whatever reason, a higher pressure will allow the system see the slight increase in pressure when the pump starts before the boiler tries to ignite. So as the pressure sensor blocks more, you need more pressure on system to see the differential.

I see, so the process is more complicated than "just some pressure in system at any time"

Thank you

Damien360

Seregwethrin wrote: »

Something got stuck in my mind though. How come the pressure sensor might be faulty, so boiler faults F9 but I can see the right pressure on the boiler's digital screen?

So it prints 1.4 bar etc right pressure but still faults F9?

I’m not sure that the fault is actually low pressure or failure to see a pressure differential when the pump starts. For whatever reason, a higher pressure will allow the system see the slight increase in pressure when the pump starts before the boiler tries to ignite. So as the pressure sensor blocks more, you need more pressure on system to see the differential.

Seregwethrin

Something got stuck in my mind though. How come the pressure sensor might be faulty, so boiler faults F9 but I can see the right pressure on the boiler's digital screen?

So it prints 1.4 bar etc right pressure but still faults F9?

John.G

I've often wondered why systems are semi sealed apart from "curing" OV systems that have air ingress problems, I have done this for a few people (not around here) with great success. Bord Gais installed a few of those Glowworm 18kw boilers around here and even though all these houses have a outstanding OV system with a very simple combined vent & cold feed which works perfectly with no air ingress or pump over they still converted them to semi sealed. The only difference that I can see is that the pressure will rise slightly on system heat up but is exactly the same with a cold system, it may be their standard procedure when installing in a OV system.

K.Flyer

John.G wrote: »

That's very interesting, logically, even with a low pressure system, a faulty pump should also still trigger this F9.

I've was caught out a couple of times thinking it's just the switch, when the pump would appear to be functioning ok.
The Glowworm workaround for low pressure systems should really only be used when there is a permanent feed from a header tank (semi-sealed) as you are doing away with the one item that will prevent damage should the system start to run out of water due to a leak.
For typical open vented systems the Heat Only model should be installed, no internal pump and no pressure switch, but it still has a safety lockout in the event of poor circulation.

John.G

That's very interesting, logically, even with a low pressure system, a faulty pump should also still trigger this F9.

K.Flyer

Unfortunately the pressure sensors on these boilers are cack and will go faulty for almost no reason.
If I remember correctly it also relies on a pressure differential from the action of the pump coming on. There are several wires coming from the switch, it's not just an on / off two wire switch. Older Ideal boilers were the same, the cold static pressure could be fine, but a weak pump would not trigger the switch, so no ignition.

Damien360

John.G wrote: »

Thanks, You now have a 30HX boiler, does this mean, in your opinion, that there is now NO low pressure alarm as the boiler pressure display is also in operative.?

Correct. It just shows the temperature setting. Definitely no pressure reading other than my manual gauge in hot press.

John.G

Damien360 wrote: »

When the sensor is new it will f9 fault for low pressure at anything below 1 bar read on system. But as the sensor goes tits up, it will give the same fault at higher and higher pressure readings. The actual pressure won’t have changed but the electronic reading will keep climbing over months on its own and the only way to fix was to increase system pressure. Even at new the sensor has a 0.4bar differential from actual. I have the 30sx. With the electronic low pressure conversion it now works as a 30hx. And it fires first time every time now.

Thanks, You now have a 30HX boiler, does this mean, in your opinion, that there is now NO low pressure alarm as the boiler pressure display is also in operative.?

Seregwethrin

Damien360 wrote: »

When the sensor is new it will f9 fault for low pressure at anything below 1 bar read on system. But as the sensor goes tits up, it will give the same fault at higher and higher pressure readings. The actual pressure won’t have changed but the electronic reading will keep climbing over months on its own and the only way to fix was to increase system pressure. Even at new the sensor has a 0.4bar differential from actual. I have the 30sx. With the electronic low pressure conversion it now works as a 30hx. And it fires first time every time now.

My experience was similar. A few months ago the boiler didn't run with 1.1-1.2bar pressure, 2 weeks ago it was 1.4 bar, now 1.6 bar...

Damien360

John.G wrote: »

What pressure does it alarm at? or maybe there's no alarm as a low pressure system is essentially a gravity fed system with a header tank fed with a endless supply of ballcock fed mains water.

My neighbor has a 2013 Glowworm Flexicom 18 SX which has never given a ounce of trouble, I would think that it has a "low pressure" configuration because it has a semi sealed system where the pressure will fall to ~ 0.4 bar every time the system cools down.

When the sensor is new it will f9 fault for low pressure at anything below 1 bar read on system. But as the sensor goes tits up, it will give the same fault at higher and higher pressure readings. The actual pressure won’t have changed but the electronic reading will keep climbing over months on its own and the only way to fix was to increase system pressure. Even at new the sensor has a 0.4bar differential from actual. I have the 30sx. With the electronic low pressure conversion it now works as a 30hx. And it fires first time every time now.

John.G

What pressure does it alarm at? or maybe there's no alarm as a low pressure system is essentially a gravity fed system with a header tank fed with a endless supply of ballcock fed mains water.

My neighbor has a 2013 Glowworm Flexicom 18 SX which has never given a ounce of trouble, I would think that it has a "low pressure" configuration because it has a semi sealed system where the pressure will fall to ~ 0.4 bar every time the system cools down.

Damien360

Seregwethrin wrote: »

Hi John,

Thank you for your insight.

yes, with higher pressure around 1.6-1.7 bar at cold the boiler ran without any failure this morning. Higher pressure seems to mitigate the issue for now.

So my understanding is you think the pressure sensor is more likely to cause this but not the circ pump, though the circ pump also doesn't sound healthy and might be faulty too as a separate issue

This is the same game I had with the pressure sensor. It will work at 1.7 now but wait a few months and you will be chasing higher and higher pressure on your system to get it working.

But you are now diluting your anti corrosion liquid in the system and will have to recharge with it at some point.

The pressure sensor replacement is the only fix and then bleed the system back to lower pressure. But in my experience and that of my plumber (brother in law), the sensor has a life of 18 months before the whole cycle starts again. Glow worm know this is a fault but offer no fix as they use the same crap sensor.

I set my system to 1.2 bar at the hot press and leave the boiler in low pressure mode. My system is a closed system and I can top it up if the pressure goes too low. I don’t have leaks and the system can hold 1.2bar for a very long time. I found it struggled and suspected but couldn’t find a leak at higher pressures.

I honestly couldn’t recommend a glow worm to anyone. This fault has taken years to get to the bottom of.

Seregwethrin

John.G wrote: »

Reading through these posts it would seem to me that the problem has nothing to do with a faulty circ pump as this has no effect on the boiler pressure, a faulty pump will cause the boiler to reach its set point temperature very rapidly and will never heat any system. As stated you seem to have a problem with the pressure sensor but once you increase the filling pressure to reset the pressure "switch" the boiler will then start and because the system then heats up, the system pressure increases due to expansion and keeps the trip further away.
Converting to a low pressure system, while a temporary fix, is not designed as such and is designed for a open vented system where the system (head) pressure will never be > 0.35 to ~ 0.5 bar.
Again IMO, you have two choices, change the setting to "low pressure" which seems relatively easy to configure or increase the cold filling pressure to say 1,7/1.8 bar but ensure that it doesn,t reach 3.0 bar when hot which will lift the PRV.
You have a pressure gauge in the hot press so allow 0.25 bar for elevation and fill to 1.65 bar on this P.gauge, the boiler P.gauge, if reading correctly should then read ~ 1.8 bar.
Of the two "fixes" changing the boiler parameters would seem the best temporary fix, you could then test the F9 trip by reducing the system pressure (cold) until it operates, at least you then know that you still have protection.

The circ pump/fan fault should obviously be repaired ASAP.

Hi John,

Thank you for your insight.

yes, with higher pressure around 1.6-1.7 bar at cold the boiler ran without any failure this morning. Higher pressure seems to mitigate the issue for now.

So my understanding is you think the pressure sensor is more likely to cause this but not the circ pump, though the circ pump also doesn't sound healthy and might be faulty too as a separate issue

John.G

Reading through these posts it would seem to me that the problem has nothing to do with a faulty circ pump as this has no effect on the boiler pressure, a faulty pump will cause the boiler to reach its set point temperature very rapidly and will never heat any system. As stated you seem to have a problem with the pressure sensor but once you increase the filling pressure to reset the pressure "switch" the boiler will then start and because the system then heats up, the system pressure increases due to expansion and keeps the trip further away.
Converting to a low pressure system, while a temporary fix, is not designed as such and is designed for a open vented system where the system (head) pressure will never be > 0.35 to ~ 0.5 bar.
Again IMO, you have two choices, change the setting to "low pressure" which seems relatively easy to configure or increase the cold filling pressure to say 1,7/1.8 bar but ensure that it doesn,t reach 3.0 bar when hot which will lift the PRV.
You have a pressure gauge in the hot press so allow 0.25 bar for elevation and fill to 1.65 bar on this P.gauge, the boiler P.gauge, if reading correctly should then read ~ 1.8 bar.
Of the two "fixes" changing the boiler parameters would seem the best temporary fix, you could then test the F9 trip by reducing the system pressure (cold) until it operates, at least you then know that you still have protection.

The circ pump/fan fault should obviously be repaired ASAP.

Seregwethrin

K.Flyer wrote: »

Now that's a pain. Is there no immersion installed, or just not working. Get that fixed as well.

I don't think any installed, there is electricity in hot press for alarm box but no immersion control unit, unless it was taken off.

Even the tank is not insulated, just wrapped with a jacket. I think it's over 20+ years old, so I wouldn't be surprised if it was never installed.

Maybe the whole tank needs to be replaced too with pipe powerflush and pressure sensor and boiler's pump replacements.

Might as well have a new heating system installed all around haha

Seregwethrin

Charlie19 wrote: »

Is this not a air problem in the pump? Or jammed pump.

From my memory a long shaft flat head screwdriver dos the trick.

I have a long shaft flat head driver... but I assume you mean using it to release the air in the pump and it's not DIY..?

K.Flyer

Seregwethrin wrote: »

I lose like 0.1 bar over 2-3 weeks. I know one rads leaks some drops sometimes I will fix that with wrapping tape around the joint, I should get to it it might help.

Yeah, get the leak fixed. Get whoever is out to the boiler to fix it.

Seregwethrin wrote: »

I don't have immersion heating in hot cyclinder it's heated only through the boiler. Hot water is the bigger problem more than heating...

Now that's a pain. Is there no immersion installed, or just not working. Get that fixed as well.

Charlie19

Is this not a air problem in the pump? Or jammed pump.

From my memory a long shaft flat head screwdriver dos the trick.

Seregwethrin

K.Flyer wrote: »

Oh yes, forgot about that rattle in the pump.
I know it would be a pain in the proverbial, but it might be best to try avoid using it in case you do further damage.
Are you constantly loosing pressure?
Using the conversion as previously posted may get you over the week, But, if your pump is weak and that's causing your F9, you may end up creating a different problem for yourself.
At best the boiler may overheat and just lock out, at worse it may do irreparable damage to the heat exchanger.
The conversion is meant to be only used when the boiler is installed where the system filling supply is too low to bring the heating system pressure above the low pressure threshold, but where the system has a constant water supply, usually from a header tank in the attic.

I would advise having this seen to as soon as possible.
Would using the immersion to heat water and buying a few electric oil filled heaters not do for the moment until it's seen to.

I lose like 0.1 bar over 2-3 weeks. I know one of the rads leaks some drops sometimes I will fix that with wrapping tape around the joint, I should get to it it might help.

I don't have immersion heating in hot cyclinder

it's heated only through the boiler. Hot water is the bigger problem more than heating the house...

K.Flyer

Seregwethrin wrote: »

Hmmm thank you for this K.Flyer but I don't think I can let the boiler running because it does knocking/kicking sound if you remember one of my previous threads and it is more often and stronger when it's running. It wouldn't let me sleep... This is such a problematic boiler and piping system I am having...

If it doesn't run maybe I can bleed the rads, lower the pressure to 1 bar, get F9 and then top up again to trick the boiler of an increased pressure maybe...

Oh yes, forgot about that rattle in the pump.
I know it would be a pain in the proverbial, but it might be best to try avoid using it in case you do further damage.
Are you constantly loosing pressure?
Using the conversion as previously posted may get you over the week, But, if your pump is weak and that's causing your F9, you may end up creating a different problem for yourself.
At best the boiler may overheat and just lock out, at worse it may do irreparable damage to the heat exchanger.
The conversion is meant to be only used when the boiler is installed where the system filling supply is too low to bring the heating system pressure above the low pressure threshold, but where the system has a constant water supply, usually from a header tank in the attic.

I would advise having this seen to as soon as possible.
Would using the immersion to heat water and buying a few electric oil filled heaters not do for the moment until it's seen to.

Seregwethrin

Damien360 wrote: »

I had the exact same issue. It’s a known fault with the pressure sensor. I have a manual pressure gauge on the line and it reads 1.2 bar consistently. But I was getting 1.7 bar at the glow worm. Had previously got the pressure sensor replaced twice for the exact same issue and finally had enough. There is a way to convert the system into a low pressure system. I got it from my plumber and it works perfectly. It requires reprogramming via the front switches and does not require removal of any panels. The conversion is officially from glow worm makers. I suggest you make sure you have a manual gauge on the line as you no longer get a reading once you convert. See attached pics.

Oh I get what you mean, that is smart! I already have a manual pressure gauge in the hotpress, I will definitely try this. Thank you a lot Damien360

I guess then I should just be careful not to run the boiler if the pressure is less than 1 bar after this because it loses pressure over time very slowly

Damien360

I had the exact same issue. It’s a known fault with the pressure sensor. I have a manual pressure gauge on the line and it reads 1.2 bar consistently. But I was getting 1.7 bar at the glow worm. Had previously got the pressure sensor replaced twice for the exact same issue and finally had enough. There is a way to convert the system into a low pressure system. I got it from my plumber and it works perfectly. It requires reprogramming via the front switches and does not require removal of any panels. The conversion is officially from glow worm makers. I suggest you make sure you have a manual gauge on the line as you no longer get a reading once you convert. See attached pics.

Seregwethrin

Hmmm thank you for this K.Flyer but I don't think I can let the boiler running because it does knocking/kicking sound if you remember one of my previous threads and it is more often and stronger when it's running. It wouldn't let me sleep... This is such a problematic boiler and piping system I am having...

If it doesn't run maybe I can bleed the rads, lower the pressure to 1 bar, get F9 and then top up again to trick the boiler of an increased pressure maybe...