Posting a message to the forum will remove the above advertisement

Discuss Worcester heatslave 15/19 not firing up, no lockout showing in the Oil and Solid Fuel Forum area at

  1. Balmeadie

    Balmeadie New Member

    Can anyone help

    I posted this in the central heating forum and was advised to try this forum instead. It's looking like this is my last attempt at a diagnosis before calling out an oftec engineer

    My problem

    1. I came back from a weekend away to find my boiler with no pressure and a circulating pump making a strange noise, no lockout was showing.
    2. I changed out the pump, found why the system had lost pressure( blocked expansion vessel hose caused the PRV to activate. no inhibitor from the looks of the gunk coming out when fully drained.)
    3. Repressurised system called for hot water and heat, circulating pump runs, no lockout
    4. Boiler didn't fire so I pressed the manual override button on the underside of the control panel.
    5. Got a blown 3amp control panel fuse for my trouble!

    Where do I go next, is it the pcb thats knackered or is it one of the thermostats or something else?
    would a knackered manual override thermostat stop the burner from firing up or has it blown the control unit on the burner unit?
    its very cold up here so any help to get us up and running again would be hugely appreciated.
  2. Best

    Best Trusted Plumber Top Contributor!!

    As I mentioned on your last post, - you need the electrics tested at your boiler before anyone can proceed. If you can't use a multimeter and not familiar with electrics, then definitely get someone in to find and remove the fault
  3. Balmeadie

    Balmeadie New Member

    I'm happy using a multimeter it's more where the logical place to start is and how to isolate the various potential culprits I.e stats, pcb, burner control unit etc. Can the stats be individually tested or would a fault in one not produce the symptoms that I've got? My experience with local firms so far has been less fault finding and more changing out parts until they find the fault which can get v. Expensive. I know that this is not the way most reputable firms operate but unfortunately I've yet to find one.
  4. Dotty

    Dotty Guest

    Whereabouts are you. Plenty of reputable guys on here. .
    • Like Like x 1
  5. Best

    Best Trusted Plumber Top Contributor!!

    I did suggest to the OP on their initial post on Central Heating part of forum to post on looking for a plumber.
  6. DaveyHep

    DaveyHep New Member

    First thing I would do is check the things that have changed....have you double checked the wiring of the pump you changed ?
    Did you disturb anything else ?
    Is the wiring in good order ?
  7. Balmeadie

    Balmeadie New Member

    Thanks DaveyHep, some sound practical advice,
    I've started to work my way back through the things that have been either disconnected or inadvertently moved. This in itself is quite a job as I've replaced the baffles, a leaking isolation valve, a blocked expansion vessel pipe, a weeping PRV and a goosed circulation pump. If there was ever an advert required for why people should service and dose their systems then this is it. Unfortunately these are all inherited problems for me. I'll report back if I find a culprit and maybe seek further advice!!
  8. DaveyHep

    DaveyHep New Member

    Only an electrical fault would cause the fuse to blow - not the wet bits.
    I'd start with the pump you replaced.
  9. SimonG

    SimonG Trusted Plumber

    You will probably find that it's either a bit that's wet that shouldn't be or on the burner.

    As Best said yesterday, get somebody in who knows what they are doing before you blow don't have else.
  10. johnf

    johnf Active Member

    Unplug the burner. Reset the overheat stat and see if it holds. If the fuse does not blow it is an issue with the burner. If it blows you will know it is before the burner.
    • Like Like x 1
  11. Balmeadie

    Balmeadie New Member

    Thanks for everyone's advice and fault finding tips, I've got to the bottom of the problem at last. As always it's embarrassingly simple but in the spirit of the forum I'm happy to share it in order that if it happens to someone else they may get a heads up!
    On closer inspection I had damaged a pin on the power lead connecting the burner to the control panel. Probably in my haste to get everything put back together and fired up. It only blew the fuse the once after that there was just no power to the burner but power to the pcb. Following DaveyHep's advice I traced my previous steps testing the circ pump first then the wiring. This is when I found the broken pin. Unfortunately my only spare was a different size 6 pin connector which meant changing out the whole thing but it's all done now and running sweet. Many thanks, keep up the good work you all provide invaluable advice for those of us who are practically capable but lacking in knowledge!!
    • Like Like x 2
  12. DaveyHep

    DaveyHep New Member

    Thanks for feeding back the outcome. So many folk come onto forums (fora ?) asking for advice then are never heard from again.
    Remember....its only ever simple AFTER you've found the problem.
    Well done you.
    • Like Like x 2
Similar Threads - Worcester heatslave firing Forum Date
Want to add immersion heater to Worcester Heatslave 20/25 Oil and Solid Fuel Forum Aug 23, 2017
Worcester Greenstar Heatslave 12-18 Rad Capacity Central Heating Forum Jul 19, 2017