How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site. Ask follow up questions if you need to.
  • Go back-and-forth until satisfied
    Rate the answer you receive.
Ask Tim Cooke Your Own Question
Tim Cooke
Tim Cooke,
Category: HVAC
Satisfied Customers: 1292
Experience:  Owner at Self-employed
Type Your HVAC Question Here...
Tim Cooke is online now

Have a Glowarm Flexicom 18sx boiler. It's just been serviced

This answer was rated:

Have a Glowarm Flexicom 18sx boiler. It's just been serviced a couple of weeks ago. The trouble may have been caused by the storms we've had recently and I suspect the pilot light has gone out. The display is reading F9 and although I've reset it by the button on the boiler's facia, there is no response aside from a motor st arting for 20 seconds onl y to show the F9 again
JA: What happened just before your boiler displayed this message?
Customer: It had been okay for the morning until the normal switch off at 10 am. It hasn't started the evening cycle
JA: How long has this been going on with your boiler? What have you tried so far?
Customer: Intermittently over the last few days. Just tried resetting the button on the front of the boiler
JA: Anything else we should know to help you best?
Customer: It's been serviced a couple of weeks ago

Hello, the high winds have certainly caused some problems, however your boiler doesn't have a pilot light that can blow out.

F9 suggest that the system pressure is low. Have you checked the system pressure? If you decide to increase it, please tell me the value before you do it and the new value after you've done it.

Also, please press the '-' button for at least 5 seconds, until 'S' begins to flash, and tell me what number is *****

Customer: replied 7 months ago.
1.4 then 9.1
9.1 bar?!!!Why did you increase it?
Customer: replied 7 months ago.
The display went back to F9 and I reset it and showed 14. The pump started again and the boiler followed with the radiators heating up. The display reads 42 now after climbing from 14. There is no full stop between the numbers. What does this all mean?
Customer: replied 7 months ago.
After 5 or 6 minutes, the reading says 51. Is this the temperature? Tried reducing the read from 51 using the "-" button for a few seconds but with no success.

Please don't take this the wrong way, but it's going to be really hard to guide you if you don't follow my suggestion and instead do several random things that yield a bunch of numbers.

Before I suggest the next step, and preferably before you touch anything else, I need to know the current system pressure.

Customer: replied 7 months ago.
Just looked at the reading which is 59, not 5.9, but 59. I had another resident check the display and he agrees, no decimal at all
Customer: replied 7 months ago.
i'm off to have a cup of tea and a smoke. Will be back in 5 minutes.
When the boiler is running, 59 is likely to be the current flow temperature.I need to know the system pressure.
Customer: replied 7 months ago.
How do I find that? There is only one display.
Customer: replied 7 months ago.
I'll check the reading again to check. I'll be a few minutes as the boiler is on the top floor!
I can send you a copy of the manual if you don’t have it?
Customer: replied 7 months ago.
I've not touched any buttons but what is the "Mode" button? Would I find the water pressure by pressing that?
Customer: replied 7 months ago.
oh! I've just found your answer re the manual. Yes, please send one to me. Many thanks!

Please see the attached document.

Reading the pressure is covered in section 11.1 on page 37.

Customer: replied 7 months ago.
Thanks Tim. I'm off upstairs to read pressure now. Show only be a few moments!
Customer: replied 7 months ago.
Pressure is 2.3
Customer: replied 7 months ago.
Pressure is now 2.2 a few minutes after 1st reading. Willl go for another cup of tea and a smoke and then take another reading. I'll be 7 or 8 minutes.
Customer: replied 7 months ago.
Pressure is 1.8 now and presumably it will continue to drop as long as the boiler is not on. Will I turn the boiler back on by pressing "Mode" and "+"? I will wait until I hear from you!

The pressure should not be dropping like that. If it was 1.4 before you increased it, and if it really was 9.1 bar afterwards, then I expect you've added a new problem.

This topic will stay open until you're happy that the boiler is working and stable, so I expect we'll be exchanging posts tomorrow at some point (as well as later tonight perhaps).

Customer: replied 7 months ago.
I agree it's time to call it a night, Tim. Actually I will close this topic. I will leave the boiler as it is. I will also contact my Glowarm engineer tomorrow to return to investigate if they do work Saturdays. We have 2 boilers in this old house. We can live on one boiler and will use electric heaters in any affected rooms. Many thanks for your help and the need to be cautious! Best wishes - Gregory

OK Gregory. Good luck with the Glowworm engineer.

If you're happy with how I've helped, your rating (using the five stars at the top of this page) will enable me to receive a credit for my time.

Tim Cooke and 2 other HVAC Specialists are ready to help you