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hours

An hour (symbol: h; also abbreviated hr) is a unit of time conventionally reckoned as 1⁄24 of a day and scientifically reckoned as 3,599–3,601 seconds, depending on conditions. There are 60 minutes in an hour, and 24 hours in a day.
The hour was initially established in the ancient Near East as a variable measure of 1⁄12 of the night or daytime. Such seasonal, temporal, or unequal hours varied by season and latitude.
Equal or equinoctial hours were taken as 1⁄24 of the day as measured from noon to noon; the minor seasonal variations of this unit were eventually smoothed by making it 1⁄24 of the mean solar day. Since this unit was not constant due to long term variations in the Earth's rotation, the hour was finally separated from the Earth's rotation and defined in terms of the atomic or physical second.
In the modern metric system, hours are an accepted unit of time defined as 3,600 atomic seconds. However, on rare occasions an hour may incorporate a positive or negative leap second, making it last 3,599 or 3,601 seconds, in order to keep it within 0.9 seconds of UT1, which is based on measurements of the mean solar day.

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  1. T

    AGA Going out after 12 to 36 hours

    Have a problem with an oil fired AGA conversion Has been no problem for 5 years, now goes out 12 to 36 hours after lighting, have checked fire valve, and have installed seperate line from tank to feed AGA went for 3 weeks one time, then went out due high winds. Has now started same pattern Help...
  2. K

    Did I pay too much and can I get any back?

    Roto Rooter took 12 hrs labor for1 person to lay 20ft of new mainline into my house. Rent a trencher, drive four hours my estimate is7000.couldn't be more than 1000worth of parts etc. Do I have a right to ask for proper pricing or is that actually right?
  3. Chuck0008

    Shut off water for a few hours. Turned water back on and leak stopped

    Bad leak inside bathroom walls at floor for three days. A gallon every hour. Shut off water for a few hours and leak stopped. Turned water back on and leak has not come back. What happened?
  4. B

    Secondary return cools cylinder within 2 hours

    I'm a plumbing novice so first of all I apologise if I'm not explaining this situation correctly. I've recently renovated a house for my family to live in and we're having an issue with water not staying hot when the secondary return circuit is on. From a starting point of fully heated the...
  5. S

    Baxi Combi 105e: CH lost 1 bar of pressure in a few hours

    Hi everyone Summary is in the title. Found the boiler was at 0.5 bar earlier today so topped up to 1.5 bar. Checked before bed and its back to 0.5 bar. There are no signs of a leak around any radiators nor any suspicious water damage on the downstairs ceiling. Before I rip up all the flooring...
  6. M

    ufh heating on 20+ hours a day

    As above. Ideally it'd be less. This might be the wrong forum for the Q. But the system is actually working fine. the system is in the 15mm insulation boards above a tar subfloor. Are my next steps to start getting cavity wall insulation etc etc?
  7. N

    Baxi combo boiler leak from DHW when not used for 5-6 hours

    Hi I have a BAXI NETA-TEC COMBI 33 GA boiler and every morning I come down to a small puddle of water underneath the boiler. The gas engineer has replaced two washers in the DHW and a new baxi brass adapter and tightens all connections, still the leak remains. It does not leak when the hot...
  8. S

    Central Heating taking two hours to warm up

    Hello, I'm not a plumber, and may get some of the terminology wrong in this post, please don't shoot me down for it. Since moving in to our home several years ago, we've had issues with the performance of our central heating. In winter, the living room can take up to two hours to get upto 18C...
  9. J

    CH pipes creaking for hours after heating turned off. Any ideas?

    Hi, recently moved into my first house and am fairly new to DIY. I've been experiencing issues with banging and creaking central heating pipes since I moved in. I've now lagged and secured piping wherever I can access it which has fixed the issue to some degree however fitted wardrobes are...
    • Josh95
    • Thread
    • after america central heating system heating hours ideas pipes turned usa
    • Replies: 3
    • Forum: USA
  10. Inverness

    Riello rdb 3 going for 2 hours then cutting out

    Hi guys, riello burner is cutting out after it’s been running for 2 hours solid. Replaced new photo cell, nozzle, capacitor, I’m trying to fit a new solenoid tomorrow. Any ideas if this fails? Thanks
  11. Dan

    Members logged in over past 24 hours

    Total: 634 users (per 24 hours) This figure is public and on the forums homepage (in the sidebar) so if anybody ever clocks it higher than this, please reply and record it for us. :) A nice record to beat. See what it is tomorrow. A mass PM has been sent out so this isn't natural members but...
  12. Plumbase Spares

    Exclusive Endfeed Fittings offer - 24 HOURS ONLY

    Consisting of quality Endfeed fittings, that are WRAS approved and manufactured to EN1254-1, this pack provides all the fittings you need for standard water and gas application in an easy to handle and store bucket. CLICK HERE
  13. T

    Boiler turning off 2 hours after Central heating timer comes on. Only fires up again with...

    Afternoon! I seem to have an issue with my central heating staying on. As its winter, we have it set on a timer. The first couple of cold days it worked fine with no problems. (on in the morning for a few hours / then again in the evening from 6pm until around 10pm). The last couple of...
  14. R

    Knocking sound in pipes for hours after last use

    Hi there, I've recently moved house into an old property (built 1938). Something that keeps me awake at night is an intermittent knocking coming from somewhere in the walls, that I believe must be the plumbing (doesn't sound like the house 'settling'). It's not Really loud (not deafening), but...
  15. J

    Out of normal working hours, rates

    Hello all Forgive me if this has been brought up before but I have a customer who wants a dishwasher connecting.. simple enough, or so I thought. However when I speak to him it turns out he cant get home till 1730 and the dishwasher isn't a straight swap, it requires new pipe work to be...
  16. C

    Expansion Vessel losing all pressure in hours?

    Hi All, Bit clueless here, but wanted some advice if possible. We had a new 200ltr unvented system installed recently. All seemed fine, however the CH kept turning off and rads going cold. I checked the EV in the loft, and it's pressure gauge had dropped to 0. I opened the valves up and...
  17. moonlight

    Emergency Plumber. Out of hours.

    I dont think the person who did this should call themselves a Plumber:eek: No wonder the toilet kept running :eek:. Nice new valve fitted. Trading standards now involved.
  18. Dan

    30-odd hours, 189 replies, 2,100+ views

    Posted this thread Friday around 5pm. http://www.ukplumbersforums.co.uk/threads/which-plumbing-suppliers-do-you-use-well-create-a-poll-once-we-have-a-list.96694/ Got 189 replies, 2,100+ views as of now. And they're still coming in very several minutes on average. So we can get people to a...
  19. Dan

    New record: most online users in 24 hours

  20. A

    Potterton Suprima. Runs for few hours then shuts down, red light.

    Hi Potterton Suprima I have to look at, red flashing light. Will not reset on button. if it's switched off at the wall then switched back on it fires up fine and will run for a few hours no problem. Goes off again, will not relight. What would you be checking? I'm thinking slow running...
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