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Discuss Only one working radiator in the Central Heating Forum area at

  1. CHRI1111

    CHRI1111 New Member

    Hello all,

    I was hoping someone could help me solve and repair my central heating issue.

    Only a single radiator works in the property in the bathroom.

    This room is located directly above the boiler on the first floor. The boiler is located within the kitchen on the ground floor.

    I notice when the boiler fires up the pump says 1 watt, then a few seconds later has two dashes.

    All the other radiators are stone dead cold.

    Any ideas?







  2. CHRI1111

    CHRI1111 New Member

    A second radiator in the adjacent bedroom is warming up, to include its outlet pipe.

    The third radiator in the second bedroom is cold, but notice the inlet pipe is luke warm. The central heating system has now been on for 30 minutes.

    When I tested the system in Winter 2016 only one radiator got hot, so a little improvement since then for some reason.

  3. ShaunCorbs

    ShaunCorbs S. Mod Trusted Plumber GSR Top Contributor!!

    Take the trv heads off and does the pin push down ? Also lift it till it stops don't force it up too much you should have heating
  4. JCplumb

    JCplumb Plumber

    The only reference I can find to the 2 dashes shown in your pic is here:
    It seems to be an indication that the supply voltage is too low.
    Whether that's normal when there is no call for the pump to run I don't know. Hopefully someone else on here has more experience with this particular pump.
    The fact that only one rad upstairs above the boiler is getting hot indicates a pump problem most of the time. Your boiler may also lock out during calls for heating because the hot water isn't dispersing quickly enough.
    Doesn't look like you have access to check the return pipe temp while it's running.
    I'd say most people would need to call a heating engineer in this situation.
  5. CHRI1111

    CHRI1111 New Member

    My boiler does keep cutting out, so I suspect the pump is either jammed or faulty?
  6. ShaunCorbs

    ShaunCorbs S. Mod Trusted Plumber GSR Top Contributor!!

    Try this

    Press and keep pressing the grey arrow point so it fills the II mark
  7. CHRI1111

    CHRI1111 New Member

    This is the trv. Does push down.

  8. CHRI1111

    CHRI1111 New Member

    I've pressed the arrow some 40 times but nothing has changed on the display
  9. CHRI1111

    CHRI1111 New Member

    I've also put my hand on the pump and cannot feel it vibrating.
  10. ShaunCorbs

    ShaunCorbs S. Mod Trusted Plumber GSR Top Contributor!!

    While it's on / got power?
  11. CHRI1111

    CHRI1111 New Member

  12. ShaunCorbs

    ShaunCorbs S. Mod Trusted Plumber GSR Top Contributor!!

    Are the other trvs like this one easy to push down and up ?
  13. ShaunCorbs

    ShaunCorbs S. Mod Trusted Plumber GSR Top Contributor!!

    I would say new pump then sorry to say

    Should adjust
  14. CHRI1111

    CHRI1111 New Member

    The other upstairs radiators don't have trv's - got these:

    Not sure how to check these?


  15. ShaunCorbs

    ShaunCorbs S. Mod Trusted Plumber GSR Top Contributor!!

    That's fine there lockshield valves won't go wrong unless there shut (anti clockwise to open if your wondering) but if they've worked before leave them point to either controller not giving power to the pump or duff pump

    Do you have a multi meter?
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