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  • FIRST POST
    • TuppenceHapenny
    • By TuppenceHapenny 28th Nov 17, 1:17 PM
    • 15Posts
    • 1Thanks
    TuppenceHapenny
    Gas Boiler wont re-light
    • #1
    • 28th Nov 17, 1:17 PM
    Gas Boiler wont re-light 28th Nov 17 at 1:17 PM
    This question concerns a Glow-worm Space Saver 50 MkII (Open Flue) boiler.

    My gas boiler has been turned off for several months while I have done a repair to the central heating system and cleaned out the radiators. For good measure I have now refilled the system with water and cleaning fluid (Fernox F3 Cleaner). After refilling, I tried to re-light the boiler so I could turn on the central heating and let the cleaning fluid do its job. When trying to re-light, I can see the boiler sparking but the pilot light will not come on. Other gas appliances are working so the gas supply to the house is OK.

    I have read on other forums that the problem is likely to be either the gas jet feeding the pilot light becoming choked with soot and tar and needing to be cleaned, or the flame sensor (thermocouple?) has developed a build-up and needs to be cleaned or replaced. Are these jobs easy enough to do myself (it seems to depend on how easy or hard it is to get at the pilot light)? Does the law allow me to attempt such jobs myself (without relevant qualifications)?

    Also, is it sensible to leave the system filled with water and cleaning fluid while I try to get the boiler working, or should I re-drain the system to prevent further corrosion?
Page 1
    • Gloomendoom
    • By Gloomendoom 28th Nov 17, 1:31 PM
    • 13,252 Posts
    • 17,468 Thanks
    Gloomendoom
    • #2
    • 28th Nov 17, 1:31 PM
    • #2
    • 28th Nov 17, 1:31 PM
    Have you tried lighting the pilot with a taper, rather than using the piezo igniter?
    Advice; it rhymes with mice. Advise; it rhymes with wise.
    • Alex1983
    • By Alex1983 28th Nov 17, 3:09 PM
    • 666 Posts
    • 373 Thanks
    Alex1983
    • #3
    • 28th Nov 17, 3:09 PM
    • #3
    • 28th Nov 17, 3:09 PM
    If it’s been off for a long period of time it will take a while to get the gas to purge the gas.

    I would get it serviced and they will be able to clean and unblock the pilot if necessary, you could get a new thermocouple at the same time, they are very cheap and universal.
    • Ganga
    • By Ganga 28th Nov 17, 4:09 PM
    • 867 Posts
    • 429 Thanks
    Ganga
    • #4
    • 28th Nov 17, 4:09 PM
    • #4
    • 28th Nov 17, 4:09 PM
    Have you tried lighting the pilot with a taper, rather than using the piezo igniter?
    Originally posted by Gloomendoom
    Our old Thorn Olympic was like that,you could push the electronic lighter till your thumb was sore or you could open the glass window and light it first time with a match.
    ITS NOT EASY TO GET EVERYTHING WRONG ,I HAVE TO WORK HARD TO DO IT!
    • TuppenceHapenny
    • By TuppenceHapenny 28th Nov 17, 8:52 PM
    • 15 Posts
    • 1 Thanks
    TuppenceHapenny
    • #5
    • 28th Nov 17, 8:52 PM
    • #5
    • 28th Nov 17, 8:52 PM
    Have you tried lighting the pilot with a taper, rather than using the piezo igniter?
    Originally posted by Gloomendoom

    Thanks for the reply. I've had another look and I can't see a way of getting a taper in - it looks as if I would have to start dismantling the boiler to get any access to the pilot light.
    • TuppenceHapenny
    • By TuppenceHapenny 28th Nov 17, 9:03 PM
    • 15 Posts
    • 1 Thanks
    TuppenceHapenny
    • #6
    • 28th Nov 17, 9:03 PM
    • #6
    • 28th Nov 17, 9:03 PM
    Thanks for the reply.
    If itís been off for a long period of time it will take a while to get the gas to purge the gas.
    Originally posted by Alex1983
    I've tried pushing in the relevant knob for a few minutes before pressing the igniter but still not lighting.

    I would get it serviced and they will be able to clean and unblock the pilot if necessary, you could get a new thermocouple at the same time, they are very cheap and universal.
    Originally posted by Alex1983
    I fear you are right - I will have to get someone in to repair/ service it. Do you know roughly how much I could expect to pay assuming it is just a case of doing a service and some relevant cleaning and replacing the thermocouple?
    • *j*
    • By *j* 29th Nov 17, 11:27 AM
    • 251 Posts
    • 139 Thanks
    *j*
    • #7
    • 29th Nov 17, 11:27 AM
    • #7
    • 29th Nov 17, 11:27 AM
    A faulty thermocouple wouldn't stop the pilot light from lighting. A faulty thermocouple would be indicated by the pilot light lighting correctly, but not staying on when you release the "light" button.

    If the pilot light doesn't light at all, the two most likely faults are a lack of spark or a blocked pilot light jet.

    It's an old, simple boiler. If it's been reliable for a while, don't let anyone talk you in to a fancy new "efficient" one without working out how long it would take to recoup the new boiler cost in gas price savings.
    • *j*
    • By *j* 29th Nov 17, 11:34 AM
    • 251 Posts
    • 139 Thanks
    *j*
    • #8
    • 29th Nov 17, 11:34 AM
    • #8
    • 29th Nov 17, 11:34 AM
    Also, is it sensible to leave the system filled with water and cleaning fluid while I try to get the boiler working, or should I re-drain the system to prevent further corrosion?
    Originally posted by TuppenceHapenny
    Fernox don't say about their F3, but the similar Sentinel X400 cleaner says "Where systems are badly fouled, we recommend a longer circulation period (approximately 3-4 weeks). The product is not aggressive and can be safely left in the system for extended periods."
    • dggar
    • By dggar 29th Nov 17, 1:53 PM
    • 564 Posts
    • 276 Thanks
    dggar
    • #9
    • 29th Nov 17, 1:53 PM
    • #9
    • 29th Nov 17, 1:53 PM
    on a boiler that i had (Radiation FuelSaver 18 R) in the fault finding section there is mention of the Over Heat device.
    Quoting from this:-


    "If the overheat device has operated it must be reset by pressing the reset button at the centre of the device before the pilot can be re-established"


    There could be something similar on your boiler.
    • *j*
    • By *j* 29th Nov 17, 2:44 PM
    • 251 Posts
    • 139 Thanks
    *j*
    I don't think that Glowworm Spacesaver is recent sufficiently recent to have an overheat cut-off, but here is a copy of the installation and servicing instructions, dated August '87....https://letsfixit.co.uk/wp-content/uploads/SPACE-SAVER-50-MKII.pdf

    Pages 17 onwards have some fault finding charts.
    • TuppenceHapenny
    • By TuppenceHapenny 29th Nov 17, 4:48 PM
    • 15 Posts
    • 1 Thanks
    TuppenceHapenny
    A faulty thermocouple wouldn't stop the pilot light from lighting. A faulty thermocouple would be indicated by the pilot light lighting correctly, but not staying on when you release the "light" button.

    If the pilot light doesn't light at all, the two most likely faults are a lack of spark or a blocked pilot light jet.
    Originally posted by *j*

    Thanks for the information - that seems to confirm it is likely to be a blocked pilot light jet (since I can see it sparking). Am I correct in thinking I am not allowed to clean it myself as I do not have the relevant gas qualification?
    • dggar
    • By dggar 29th Nov 17, 4:52 PM
    • 564 Posts
    • 276 Thanks
    dggar
    I don't think that Glowworm Spacesaver is recent sufficiently recent to have an overheat cut-off, but here is a copy of the installation and servicing instructions, dated August '87....https://letsfixit.co.uk/wp-content/uploads/SPACE-SAVER-50-MKII.pdf

    Pages 17 onwards have some fault finding charts.
    Originally posted by *j*

    The Boiler I quoted was installed in 1981
    • *j*
    • By *j* 29th Nov 17, 5:03 PM
    • 251 Posts
    • 139 Thanks
    *j*
    The Boiler I quoted was installed in 1981
    Originally posted by dggar
    That's good to know. Is it still in use? I hope it is!
    • *j*
    • By *j* 29th Nov 17, 5:17 PM
    • 251 Posts
    • 139 Thanks
    *j*
    Thanks for the information - that seems to confirm it is likely to be a blocked pilot light jet (since I can see it sparking). Am I correct in thinking I am not allowed to clean it myself as I do not have the relevant gas qualification?
    Originally posted by TuppenceHapenny
    I believe it depends on whether you are competent and whether you are being paid for it or not.

    But seriously, because of what could happen it's probably best to have a "proper" person come to fix it and service the boiler at the same time. You can phone to explain the problem and get an idea of the cost, then look over his/her shoulder to see how it's done.

    Remember you don't want a new boiler, and yours can be fixed.
    • dggar
    • By dggar 29th Nov 17, 5:19 PM
    • 564 Posts
    • 276 Thanks
    dggar
    That's good to know. Is it still in use? I hope it is!
    Originally posted by *j*
    Yes It still works. The part I was referring to is this
    https://www.ebay.co.uk/itm/GLOWWORM-428900-S403073-THERMOSTAT-RANCO-LM5-P8037-F-SVR-BZ3-/311724849514


    The end of the thermocouple sits in this
    https://www.catersparesuk.co.uk/product/2-wire-thermocouple-gas-valve-interrupter-high-limit-pitco-falcon-fryer-leads/


    and the leads attach to Ranco LM5
    • TuppenceHapenny
    • By TuppenceHapenny 29th Nov 17, 10:50 PM
    • 15 Posts
    • 1 Thanks
    TuppenceHapenny
    Fernox don't say about their F3, but the similar Sentinel X400 cleaner says "Where systems are badly fouled, we recommend a longer circulation period (approximately 3-4 weeks). The product is not aggressive and can be safely left in the system for extended periods."
    Originally posted by *j*
    Thanks for this. I contacted Fernox themselves and their adviser said that the F3 mixture could be left in for up to 3 weeks, so your implication is quite correct!
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