Water pressure in bathroom a bit bad.

Discussion in 'Plumbers' Talk' started by Mancone, Dec 22, 2019.

  1. Mancone

    Mancone Member

    I have a 2 bed semi, 1900s era. The water pressure in the bathroom is pretty poor. I have a separate bath and shower, plus two taps for the sink. The shower isn’t too bad, bath takes a while to fill.

    I’ve had a problem with the boiler not making the water hot in the bath but it does for the shower. I can have a shower fine and take a long time, but how water for the bath cuts of. I think I’ll need a new boiler as the three heating engineers haven’t been able to solve it. Combo boiler.

    Any ideas of what I can do?
     
  2. spirits are real 2016

    spirits are real 2016 Screwfix Select

    Is it a digital display or dials to adjust the temperature of the hot water on the boiler..
     
  3. Mancone

    Mancone Member

    There isn’t such a thing on the boiler? . The thermostat is in the hallway.
     
  4. kiaora

    kiaora Screwfix Select

    Hi
    To prove the problem you have, run to shower on hot only and using a 1 litre measuring jug, calculate the flow rate, ie. 10 seconds to fill = 6 litres per min,
    Then test bath hot tap full on, and get flow rate.

    you will probably find the flow rate at the hot tap in the bath to too fast for the boiler to heat the water.

    good luck
    Peter
     
    Mancone likes this.
  5. Mancone

    Mancone Member

    Ok. The shower I can’t isolate the hot tap because it’s on a mixer and the mixer doesn’t work properly. Having said that, the flow is fine for the shower even on hot showers.

    The bath is really slow. But it’s interesting you say that as if I run the cold tap on the
    sinks the hot water does run hot on the bath taps. A boiler man did that once, however I haven’t tried again.
     
  6. kiaora

    kiaora Screwfix Select

    hi
    just try running the hot bath tap at a slower rate,
     
  7. Mike83

    Mike83 Screwfix Select

    If the flow rate is ok at the bath and the boiler still doesn’t fire then it could be the flow switch.
    What make and model of boiler is it?
    Sometimes when the diaphragm inside the boiler gets worn it will fire for some taps but not others.
     
    Mancone likes this.
  8. Mancone

    Mancone Member

    Thanks. It’s an Ideal Logic C24 but around 7 years old. It’s got slightly different dials than the current design.
     
  9. Mancone

    Mancone Member

    Done that plenty of times. It’s just not hot.
     
  10. kiaora

    kiaora Screwfix Select

    hi
    the 24 kw combi is not really suitable for running a bath. i see in the data sheet, 9.9 lpm max flow hot water at 35 degrees rise in temperature.

    when diagnosing this type of problem, "not very Hot" and "Slow flow rate" are not helpful,
    try this...
    if you actually measure the flow and temperate difference, ie. temp of cold and temp of hot and flow rate. you will find the answer.

    also, the figures given by the manufacturer are exactly that !
    the next step, if the figures show you don't have 35 degrees temp lift, (delta T ) at 9.9 lpm. is to check the gas rate,
    the boiler data in the manual will give the information you need

    this can all be done without touching the boiler case, its quite safe.

    regards
    peter
     
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  11. Mike83

    Mike83 Screwfix Select

    Your boiler will probably have a flow turbine as it’s a bit more modern.
    A 24kw combi won’t perform that well at this time of year with running a bath.

    When the bath tap is running does the boiler actually fire up and remain lit ?
     
    Mancone likes this.
  12. Mancone

    Mancone Member

    The kitchen taps only really get hot when the central heating is on. Weird right. I’ve had two hot baths after it was fixed by an engineer (before my heating plan). So it’s possible.

    I will do what you asked when I’m home.
     
  13. Mancone

    Mancone Member

    I will do what you asked when I’m home. Why can I run a hot shower but not a bath? I’ve also had two hot baths before.
     
  14. Mancone

    Mancone Member

    The boiler get the blue burner light and also D for demand.
     
  15. Mancone

    Mancone Member

    Hi the rate I’m getting is 8.398 and the 10% tolerance is 8.91. I’m assuming you mean this

    I’ll be getting my pipes widened when I get the new boiler so I’ll have a hot bath?

    If I’ve done it right, I feel like I’m learning and becoming more competent day by day :) female and first house
     
  16. kiaora

    kiaora Screwfix Select

    hi
    if this is the gas rate with the hot bath tap on, you have cracked it !
    if its 10 kw with hot bath tap running, the problem is in the boiler, it should be around 24 kw,
    i would suggest, the diverter valve is sending water round the heating when the tap is on,

    to prove this, when the heating is off and cold, run the bath tap and feel the heating pipes from the boiler and if they get hot when water only is on, you have successfully diagnosed your problem, well done you !

    regards
    peter
     
  17. kiaora

    kiaora Screwfix Select

    btw,
    its not the pipes wider you need, its more kw, say 30 kw for bath use,
    (you may need larger gas pipe for more gas.)
     
  18. Mancone

    Mancone Member

    I just had the heating on for about an hour and turned up high. Did I need the hot water on? I just followed what she did on her video.
     
  19. Mancone

    Mancone Member

    yes a larger kw of boiler and I will need a bigger gas pipe as the current one is too small. Long story short - bigger boiler.
     
  20. kiaora

    kiaora Screwfix Select

    ah !
    nope, what we need to do, is workout how much gas is being used,(gas rate) when the bath tap is running, !

    if it were 10 kw with tap running that tells us where to look,
    stick with it !

    re-test required
     
    Mancone likes this.

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