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Intergas HRE 28/24 Hot Water Only Warm

Discussion in 'Plumbing and Central Heating' started by timbeam, 1 Jan 2016.

  1. timbeam

    timbeam

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    Hi all,

    I would really appreciate some help if possible.

    I have just had the above boiler fitted and I am finding that at full flow, the hot water only gets warm.

    I told my installer about this and his solution was to not turn the taps on full! Needless to say, I wasn't impressed with his answer.

    The flow from my cold tap seems to be quite high at about 20 l/min but I don't know what my water pressure is.

    I have tried slowing the flow using the mains stop tap and this does indeed solve the problem if I slow the flow down to about 8 l/min.

    Is there a way to reduce the flow of water through the boiler without affecting the cold water too by using the stop tap?

    Should I even be having this problem?

    Any advice would be greatly appreciated. I am disappointed to be having this problem on a brand new boiler.

    Thanks for your assistance.
     
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  3. Dan Robinson

    Dan Robinson

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    Fair enough.

    It solved the problem though.

    What is the designed flow rate of the boiler?

    Woo hoo

    Yes. Fit a flow restrictor on the inlet.
     
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  4. your boiler has a flow rate of 11lpm at a 35 deg temp rise, you have 20lpm coming in, the water passes through the boiler quicker than it's capacity to heat it.

    Learning to turn the hot tap on to a suitable amount of flow is the cheapest and easiest solution.

    This is true of all combi's and is one of there biggest limitations.
     
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  5. timbeam

    timbeam

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    Wow. I have no idea who you are Dan or what I have done to offend you but I will address your points anyway:

    Not really.

    Nope! If I only partially open the taps in my house the hot water causes the tap washer to swell and the tap turns itself off. Turn it on again, same thing happens. Turn it on again, only gets warm.

    15l/min at +25'c, 11l/min at +35'c. My installer initially recommended the Intergas 18/24 before I questioned whether this would be sufficient.

    I thought so since my solution was better than the installer's.
     
  6. timbeam

    timbeam

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    Thanks for your helpful post.

    I am frustrated because I haven't come across this problem before in any of the houses I have owned before.

    Would it be an acceptable solution to reduce the flow of cold water entering the boiler using the isolation valve on the cold feed below the boiler?

    At least this wouldn't affect the cold water flow to the house.

    Thanks for your assistance.
     
  7. jeff the gasman

    jeff the gasman

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    Open the bath tap fully and reduce the flow into the boiler gradually, using the isolator under the boiler until you are happy with th flow and temperature.
     
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  8. Dan Robinson

    Dan Robinson

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    OP, You haven't offended me, but you might.

    Thank you for acknowledging my perfect solution offered by suggesting a flow restricting valve.

    If you know the rated output of the boiler, why moan about it not providing more?

    This would be an issue with Any instantaneous water heater.

    If you are not getting the rated output, then your installer might need to upgrade your gas supply.
     
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  9. timbeam

    timbeam

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    Not moaning, perfectly happy with the flow the boiler can cope with. Just not happy that my installer hasn't done what I view as a necessary thing by restricting the flow so that I can fully open my hot taps.

    Thanks for that Jeff, that's what I was hoping I would be able to do. I assume that this is a perfectly acceptable solution and won't cause any problems for the boiler?
     
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  11. jeff the gasman

    jeff the gasman

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    Might create a little resistance noise that's all. As Dan said a suitable flow restrictor would do the job quietly and would automatically adapt to varying inlet pressures.
     
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  12. Dan Robinson

    Dan Robinson

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    Comes down to sales techniques then. When we install these we use this as a feature rather than a problem.

    Means you can get more water at a lower temperature should you need it.

    I stock the restrictors so my customers have a choice.


    You're welcome for the advice BTW.
     
  13. dilalio

    dilalio

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    Any new install is going to have its pros and cons, which will only become evident when used in anger by the "user".
    Especially if you have changed to a new method of CH and DHW, ie: Gravity to combi.
    Your installer can't possibly foresee your personal water usage habits and bathing traits.
    Your new boiler will only deliver what it says on the tin and performance will also be affected by existing pipework runs, system design and brassware.
    There will always be a teething period following which a balance must be struck between that which can be resolved and what must be accepted pragmatically!
    Try working with your installer for additional works that can be undertaken to improve things, rather than pointing a finger at him, I doubt he wants a reputation as a hit and run merchant ;)
     
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  14. timbeam

    timbeam

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    Thanks for all the advice, Dan included.

    Might just leave the stop tap reducing the flow for now and see how it goes.

    Just for background sake we have come from an Ideal Isar so we kind of expected the Intergas to be a Rolls Royce :)

    Thanks again.
     
  15. Dan Robinson

    Dan Robinson

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    There is no comparison. A candle and used baked bean can would be a significant upgrade from that sh|tbox.


    The issue with leaving the stop cock adjusted is two fold.

    You have already noticed the effect on the rest of the system.

    Also, the adjustment is not going to adjust to Pressure fluctuations. A proper flow restrictor will maintain flow rates at different pressures.


    They are less than a tenner too.
     
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  16. Agile

    Agile

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    With the Intergas the correct way to set the hot water temperature is on the boiler settings which an installer should for any customer who seems intelligent enough to understand it. I usually set to 52 C.

    I do restrict incoming flow rate to about 110% of what the boiler can heat to lessen the number of calls on this topic.

    I really have never understood why so many people think that they should always open taps fully. Surely its an easy enough idea that you can alter the temperature by how far you open a tap?

    There is a minor problem with the design of the Intergas. When being used for heating, if the flow temperature of the heating is set much above 62 C then when, water is first used, the temperature will be a bit above the set flow temperature. Mostly this just serves to counteract the cooling effect of the hot water supply pipes . But it can sometimes give rise to a complaint when the pipe run is short.

    Tony
     
    Last edited: 2 Jan 2016
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  17. Razor900

    Razor900

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    Bottom line us the installer shouldve set the flow rate when he commissioned the boiler.

    Turn your stop cock back up and run the hot water. Turn the blue valve under the boiler until you hear the sound change and it should be somewhere near
     
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