update for r2d2,water sys and jimbo

Discussion in 'Plumbers' Talk' started by jonob, Feb 8, 2007.

  1. jonob

    jonob Member

  2. jonob

    jonob Member

    the gas use was excessive a few weeks ago when the temp was seasonally warm
  3. r2d2

    r2d2 New Member

    sorry can you explain a bit more ?

    I know people that have heating costs averaging £80 weekly during the heating season purchasing oil to fire UF heating .
    Excessive fuel consumption is nothing new in large properties with UF heating.
    You can have a system which is reasonably economic to run with the right control system however. :)
  4. r2d2

    r2d2 New Member

    here pics of my manifolds do you mean put the zone valves in the flow just before the manifolds

    Yes, this is an option but you must also provide another zone valve and time clock for the rad circuit if you want to run the rad circuit separately and to prevent the rad circuit heating up when the downstairs UF heating is on.

    One zone valve will suffice as your rads and UF heating upstairs have separate actuaters and trvs fitted anyway.
    Then a separate zone valve for downstairs controlled by its own timeclock.
  5. jonob

    jonob Member

    unfortunatley its not piped up as a seperate circuit its one flow and ret and the rads and ufh spur off it so it comes from boiler then to downstairs ufh then off to 2 upstairs rads - then to upstairs ufh then off to rest of upstairs rads

    so seperate zoneing will be difficult

    but if i turn off rads and ufh temp is at 55 deg dont see how it can use so much gas

    do you ?
  6. jonob

    jonob Member

    i bought my boiler thinking that it would be econimic for heating and water

    what do you think re the water heating costs for the 1 hour
  7. jonob

    jonob Member

    a friend of mine has ufh and an oil system and he uses £300 of oil per year

    his is on low and 24hrs per day with no stats or zone valves or what ever

    he can lower his boiler temp and its at 40 deg - he has no rads
  8. doitall

    doitall New Member

    Sure I said this more than once.

    Turn the blender valve on the manifolds down to 35°c and the boiler down to around 55-60°c and try it for 24 hours, you can always ease it up a tad.

    £300 a year is ridiculas, double it and you should be happy.
  9. jonob

    jonob Member

    if you turn the blender valve down it goes too cold

    my boiler is a fully modulating one and does not allow you to adjust ch flow temp
  10. r2d2

    r2d2 New Member

    and the boiler down to around 55-60°c

    Thier is no control on the boiler to do this Doitall.

    300 a year is ridiculas

    Impossible more like , unless he is living in very small property.
  11. jonob

    jonob Member

    what about wiring the setback to the frost stat so the boiler is off overnight unless fired up by the frost stat ?
  12. jonob

    jonob Member

    bg come round and said i should be paying no more than £850 per year ?
  13. r2d2

    r2d2 New Member

    bg come round and said i should be paying no more than £850 per year ?

    Are they happy with the meter calibrations ?.
  14. jonob

    jonob Member

    no it was bg that suggested a meter check

    he said its impossible for the boiler to use that much on the load its working at , not just slightly over but impossible

    but meter check boys can come until 22 feb

    bg wrote some figures down-

    its gas rated at 23.24kw gross and 20.94 kw net

    it did .072 cu mtr on his 2 min test that was ch only - no dhw

    so it was doing 51.84 actual in 24 hrs

    and the absoulte max would be 61.20

    do these figures make sense to you ?
  15. r2d2

    r2d2 New Member

    so it was doing 51.84 actual in 24 hrs

    Yes, thats if the boiler runs continually for 24 hours non stop.
    That being the case then the boiler would be seriously undersized to meet the load.
  16. r2d2

    r2d2 New Member

    Can you place a two port valve easily on the flow to the upstairs rad circuit ??.
  17. jonob

    jonob Member

    what exactly will that do

    what about the frost stat con - im gonna try that tonight
  18. r2d2

    r2d2 New Member

    what about wiring the setback to the frost stat so the boiler is off overnight unless fired up by the frost stat ?

    Why would you want to do this ?
    You have a timing programmer which you can time to turn the system off at night.

    what exactly will that do

    If you refer to nu heats combination boiler diagrams you will see a two port valve fitted to the radiator circuit. You will also see separate timers controlling the optiflo controllers.
    <u>This is separate zoning</u>

    what about the frost stat con - im gonna try that tonight

    As I said just time the system to turn off. You have this capability I take it ?.
  19. r2d2

    r2d2 New Member

    what exactly will that do

    Prevent the upstairs rad circuit heating when downstairs UF is operating. I would have thought that was obvious.
    If you get someone competant to wire the system correctly you will have less problems.
  20. Water Systems

    Water Systems New Member

    Only problem with your calcs water systems is
    21Kw in an hour to heat the cylinder, the
    should have been up to temp in 30 mins.

    DIA, nothing wrong with the calcs. It says in 1
    to heat 150 litres 60C is takes x kW and n
    and the same for 0.75 hr, etc.

    Sorry water systems didn't mean your calcs, but
    actual total KW to perform the task

    21kw I think it was to raise the 150 ltrs 60c.

    Based on your calcs would you say that was high or
    about right.

    To heat 150 litres he measured 21kW input (2 cu
    metres in one hour, when it should be around half
    that. It takes 10kW to raise the water 60C in one

    If the boiler was checked out and it is OK, then the
    meter is at fault. Did the service man check
    pressures, etc? Did he do it properly?

    Sorry, wrong, in a hurry. He has to measure the time the cylidner takes to heat up full, in minutes and the gas used.

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