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Out of work electricians ?

Discussion in 'Electrics UK' started by bernardgreen, 10 Oct 2021.

  1. bernardgreen

    bernardgreen

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  3. ericmark

    ericmark

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    We want paying, so since no money, really would not help. I remember our winter of discontent and power only for some hours of the day, and also working on the Falklands were farms only turned on the generator twice a day, so morning power used to clean and evening power.

    Because it was how it had always been, there were no upright freezers, chest freezers last longer with no power, radio use batteries, and heating was with peat fires.

    During our winter of discontent I lived in a house with hot air central heating and no heating worked without electric, we had gas, but no electric to work fans, no heating, and we had a very small flue less gas heater installed, seem to remember limited to 850 watt output, which simply was not enough to heat the room front to back of house with floor to ceiling single glazed windows either end.

    One of the main reasons for moving was to get a house we could heat without electric, our new house had a 4.5 kW gas fire and a flue brick, and it was enough to keep whole house warm. Which begs the question why now with double glazing, cavity wall insulation, and massive amounts of loft insulation do we need a boiler of 20 kW?

    Today we have a house with an open fire, boarded up with a hole for the AC pipe to fit in during the summer, but we can if required burn the furniture to keep warm.
     
  4. Swwils

    Swwils

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    As you suggest - you don't need a boiler of 20kW, they are very often over specified by people who have no idea about the building or aren't actually heating engineers.

    My 2020 newbuild has a 30kW boiler, enough for a primary school. It probably never goes above 6kW of demand. Luckily it is one of the few that can modulate that low.
     
  5. bernardgreen

    bernardgreen

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    My large cottage has a 16 kW boiler ( heat only ) and that has been more than enough over the worse of cold weather in the last 10 years.
     
  6. plugwash

    plugwash

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    I don't know about other people, but the reason I have a 35kW boiler is to I can fill a bath in a reasonable time without having to have a tank.
     
  7. jj4091

    jj4091

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    Ditto
     
  8. bernardgreen

    bernardgreen

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    but have you considered how (in)efficient your boiler is when it only has to supply 2 or3 kW to keep the house warm. Even with 10 to 1 modulation a 35 kW boiler will be creating 3.5 kW which could easily be more heat than the house needs and therefor the boiler will begin to cycle ON and OFF which wastes gas each time it fires up. And increases wear and tear on the boiler

    And what is the boiler's efficiency when modulated down to produce only 3.5 kW, it will not be the same as when the boiler is producing the rated 35 kW

    It has gone full circle...... Combi boilers were developed to provide instant hot water in homes that were too compact ( too lacking in space ) to have a hot water cylinder. Sensible idea, but now the availability of quick and easy to install combi boilers ( preferred by many installers and housing developers ) is encouraging people to go without a cylinder.
     
  9. ericmark

    ericmark

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    I wanted the space used by the cylinder to make a third bedroom, and I fitted an intent heat boiler for the domestic hot water in the garage, not a combi, two independent boilers, this was in the 80's seem to remember called a Main 7. The boiler could modulate, but not to the extent of boilers today, and in the summer had problems with the shower it was not using enough water, but it did not require any electrical connection, so with electric power cut still had domestic hot water.

    However unless in eco mode, mothers combi boiler also stored a little hot water, it was a pain, as using shower it was cold on turn on, then the pre-heated water arrived, and you stepped under shower, but this ran out before boiler had warmed up water, so went cold again, so could only use when it went hot for second time.

    But the 40 gallon cylinder did give hot water enough for a bath without need for electric, as did the non combi boiler, not however with the combi boiler.

    But with sons narrow boat we expected times with no 230 volt power, so boiler was 12 volt powered as were the pumps, so it would depend how often power is lost as to if loss of power is a real problem. In UK with high rise flats being all electric it would be a massive problem, but no idea of how much of a problem there?
     
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  11. bernardgreen

    bernardgreen

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    That is another problem with combi boilers, when the electric supply is lost there is no way to heat water.
     
  12. ericmark

    ericmark

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    I note some Worcester Bosch ask for type A RCBO/RCD this was posted by @stem Worcester Power.jpg and I have heard some will not work without a good earth, some thing to do with the mother board, so not sure if they will work with an inverter?
     
  13. davelx

    davelx

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    My Greenstar 27 works fine off an isolated/unearthed portable generator (basic Honda, not an inverter). I've not tried it on a modified sine-wave inverter
     
  14. JohnW2

    JohnW2

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    Is that not a problem with all boilers? My ancient boiler (not to mention pumps/valves etc.) certainly needs electricity to work, which is one of the main reasons why I got a small generator many years ago.

    Kind Regards, John
     
  15. ericmark

    ericmark

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    No the old Main 7 did not need an electric supply.
     
  16. JohnW2

    JohnW2

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    I don't know what a 'Main 7" is, and/or how it got into this discussion, but my ~30 year-old Ideal boiler certainly needs an electricity supply for the gas valve to work (i.e. 'open').

    If there is no electrical control at all, how can one 'switch off the boiler' - just with a 'gas tap'?

    Kind Regards, John
     
  17. ericmark

    ericmark

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    The main 7 was for domestic hot water, not central heating, it had a pilot flame to turn it on, and the sensor in the flame generated to only electric power used. I think it was around 18 kW worked shower OK, but took ages to fill the bath.

    We also had a gas fire with flue brick, again no electric other than the flame failure device. At 4.5 kW it would heat whole house, but no thermostatic control, to be fair neither has an open fire.

    The advantage of central heating is the automation, I never remember a gas cut, sure it must happen, but not to me.

    For me a petrol/TVO generator would be great, the 28 sec gas oil is nearly TVO so engine should run on that for months with a 600 gallon tank, but it is well down on the priority list.
     
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