Pipes are frozen, tank is empty, can I use the heating?

Discussion in 'Homes and gardens' started by Petit, Jan 5, 2010.

  1. Petit

    Petit Registered User

    Posts:
    20
    Hi there,
    We are 4 days without water. We reckon the pipes are frozen. The mains went first and then we drained the tank. We now realise this was foolish. Can we still use the oil fired heating?? It's off at the moment but this weather is not improving and I'm getting mixed advice. Thanks in advance.
     
  2. onq

    onq Former user

    Posts:
    4,401
    Petit,

    You need to take competent advice.
    You must have a plumber locally you can ring.
    I would be very wary of running it if there's no water left in the Hot Water Cylinder.

    Equally you need to heat your house.
    We keep a couple of small electric blower type heaters for emergencies.
    The day we moved in was a Friday in February and the Bórd Gáis guy disappeared five minutes before we arrived.
    We had an eight month old baby and a freezing house so I nipped around to DID electrical and bought a heater to do us over the weekend.

    Also we lit the fire in the front room - no back boiler to worry about - if you have one be wary of lighting the fire.

    HTH.

    ONQ.
     
  3. Petit

    Petit Registered User

    Posts:
    20
    Thanks ONQ,

    Yes, I have a couple of portable oil heaters on the go and a fire lit all the time (no back boiler!) but like you I have a small child and it would help to put the heat on but I am wary. I'm going to ring the plumber tomorrow.

    I wish I had know this in advance I would have kept the tap on a trickle. I'm here 8 years and never had this happen! Thanks for the reply. Petit
     
  4. DavyJones

    DavyJones Frequent Poster

    Posts:
    1,975
    Use the heating, the hot water cylinder isn't empty, even if it was it has no bearing on your heating.
     
  5. Bronte

    Bronte Frequent Poster

    Posts:
    10,294
    I had pipes that bust many years ago, the plumber installed a light or heat to the pipe near the tank in the attic so it would never happen again. I'd recommend it to anyone having frozen pipe problems.
     
  6. onq

    onq Former user

    Posts:
    4,401
    How do you know the HWC has water in it?

    ONQ.
     
  7. delgirl

    delgirl Frequent Poster

    Posts:
    1,311
    My neighbour had the same problem, but was able to use his oil-fired central heating without a problem.

    He also cleverly connected a long hose to a neighbour's outside tap and was able to fill the tanks in the attic.
     
  8. SparkRite

    SparkRite Frequent Poster

    Posts:
    932
    Think about it ONQ, and then tell me how it could possibly empty?

    Clue: What drives the water through the HWC ?
     
  9. Leo

    Leo Moderator

    Posts:
    6,796
    Aw, I really want to answer that one but feel I might be spoiling ONQ's test :D
     
  10. Towger

    Towger Frequent Poster

    Posts:
    2,137
    What, I thought you were an expert on all building matter!
     
  11. W200

    W200 Frequent Poster

    Posts:
    112
    Have a look in the attic and see if there is another small water tank ( Header tank ) positioned above the main tank . So long as there is water in this tank then heating is safe to use . If you do not have a header tank then you must have a "Closed" heating system which has a pressure gauge on the system to show if there is water there. If you know where this gauge is and pressure is normal then system is safe .
     
  12. onq

    onq Former user

    Posts:
    4,401
    <chuckle>

    Oh dear, here we go...

    "Competent to comment on all matters in relation to buildings" is what I claim.

    I'm very wary of claiming expertise above and beyond that of a competent practitioner in my profession.
    [I also worked as a plumbers mate at one time but I tend to stick to what I'm good at these days].

    Hot water cylinders may have two means of heating the domestic water supply; -
    i) an electric element, the so called immersion heater
    ii) a coil fed by the boiler - the indirect heating method

    The water in the coil doesn't mix with the water in the cylinder.
    The water in the cylinder is for domestic use - HW taps, showers etc.

    A separate boiler pipe feeds the radiators - the Primary circuit - and the boiler/rad systems is kept topped up by, and expands into, an expansion tank.
    This is smaller than and often separate from the main tank.
    You can sometimes see the smaller tank perched above the larger one on older indirect systems.

    The hot water cylinder cylinder therefore regularly empties, refilled by water from the main attic tank, with hot water being drawn off to the HW taps throughout the house.
    The HWC will eventually empty if the main tank is drained and the main tank supply cut off and people continue to use the hot taps in the house.

    The Primary circuit passes into and out of the HW cylinder at top and bottom.
    Like the immersion, it is designed to heat a cylinder full of water, not full of air.
    I have seen HWCs fail at these connection points.
    Thus my concern that I would be wary of running a heating system for any length of time when the HWC is empty.

    I am happy to stand corrected or receive some wisdom on the matter.

    :)

    ONQ.

    PS I'm assuming this is the method of heating used.
    It may be an older house with a totally separate heating system in which case no problems may arise
    It may be also possible to shut of the branch to the presumably empty HWC.
     
  13. onq

    onq Former user

    Posts:
    4,401
    The OP speculated that the cause of the water supply failure was frozen pipes.

    Some residual heat may have kept the water in the header tank liquid, but the uninsulated overflow pipe in the attic might have frozen.

    Unless of course we have a plumber reading here who could state that these kinds of things never happen.

    ONQ.
     
  14. Petit

    Petit Registered User

    Posts:
    20
    Hi there, thanks for all the replies!! We reckon it is the outside pipes under pavement and field that are frozen. We don't have another house within a mile of us to feed water into our tank, sadly! The house is only 8 years old and as I say it is the first time it has happened but it is bitter here.

    Everything is frozen solid outside. Waiting for return call from plumber!! I think he's busy!
     
  15. Leo

    Leo Moderator

    Posts:
    6,796
    Good to hear that last bit :)

    The HWC fills from the bottom, drains from the top. When you open a hot tap, the pressure from the cold feed atthe bottom forces hot water out the top of the tank. Ideal really as the water at the top is the hottest within the tank. Where dual coil immersion elements are used, the shorter 'sink' coil only heats the top portion of the tank.
    Leo
     
  16. villa 1

    villa 1 Frequent Poster

    Posts:
    361
    If mains water service pipes are buried at the proper depths they will not freeze (760mm) The trouble starts when they are not deep enough and sharp sustained frosts freeze them up. Pouring boiling water over external stopcocks on pipes that are not buried deep enough will only add to the problem. Bob the builders had a habit of installing service pipes at shallow depths leading to freezing problems.
    Wait till the thaw and we'll have loads of leaks. Frozen pipes don't leak, the ice breaks pipes and connecting fittings. It's when they start defrosting the trouble occurs!!
     
  17. SparkRite

    SparkRite Frequent Poster

    Posts:
    932
    ONQ you're not stopping to think about this......

    As water is drawn from the HWC it is (normally) forced out by the driving water from the header tank.
    The amount drawn off equals the amount "gravity fed" in. Therefore, remove the "driving force" (by whatever means) and no water will flow through the HWC ie. it remains full, no matter how many taps are open.
     
  18. Dirac

    Dirac Frequent Poster

    Posts:
    99
    We had the same problem on Christmas day. Tanks were drained in attic. Turned out that pipe from well pressure vessel had frozen. Turned well pump off, closed outlet valve, undid well pipe and used the steam cleaner to shoot steam down the water pipe (mind your hands!) and then connected it all up again. Thought I had the problem fixed when I checked the header tanks in the loft had filled up but still no water running apart from kitchen and utility cold which comes straight from the inlet rather than tanks (apparently cos of better pressure for washing machine and dishwasher). Eventually located the problem. Ours is a pumped system and the pump which pumps cold water had safety cut out when no water was coming from headers. pressed the reset button and hey presto, air and water venting from taps and all sorted! Hope this helps
     
  19. onq

    onq Former user

    Posts:
    4,401
    So the colder denser water stays at the bottom and the hotter water stays at the top and is drawn off.

    Thus the level cannot fall below the outlet of the tank unless there is a leak ower down.

    I presume there is some sort of valve at the base ot drain it off it work is necessary on the tank.

    Nice to learn something again.

    I say again because I'm sure I discussed this with someone before [a plumber no doubt] and knew it, but forgot it.

    Thanks Leo.

    ONQ.
     
  20. Petit

    Petit Registered User

    Posts:
    20
    Villa 1, I think you hit the nail on the head, Bob the builder did not put them down far enough hence our problem. Still not heard from plumber!