Rinnai Infinity Problems….

[Eric Ianson]

Hi, just wondering if anyone has come across the following problems with a rinnai infinty continuous hot water heater. Basically the temp of th e water fluctuates quite drastically, most noticeably whilest in the shower. Temp drops to almost cold water and will then get hotter than the specified temp, making for a very unpleasant shower experience.

[SelgasParticipant]

Your problem could be the result of quite a number of causes but in order to assist you further would you be so kind as to inform me what gas type you are using – is it Natural Gas or LPG as one of the main causes of your complaint is more prevalent with LPG than with Natural Gas.

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Selgas Services Ltd
Craftsman Gasfitters, Plumbers, Electrical Service Technicians

[jkobierParticipant]

Thanks for the reply.

Gas is mains connected Natural Gas.

Worth mentioning also is that we have had the mains pressure checked twice – being told both times that the pressure was sufficient.

We also have a Vulcan ducted gas heater that every now and then turns itself off, according to the error message, due to low gas pressure. Mind you this has only happened 3 or 4 times, we have had this serviced and examined adn been told that there does not appear to have any problems.

The problem with the Infinity occurs 9 times out of 10 while showering. I thought that the distance from the heating unit to the shower might have something to do with it but the temperature fluctuates from very hot to cold. I thought distance would result in a gradual increase up to the correct temperature.

Any help appreciated!

[SelgasParticipant]

Given the information you have now advised I am almost certain that your problem with the Infinity is due in the main to a lack of gas supply pressure or volume. Contact your gas supplier and have them check out the outlet supply pressure from your gas meter set and when they are undertaking that test turn on the hot tap on full and let them check the pressure drop. My logic behind this consideration is simply that you have suffered a similar problem allbeit not so often with your central heating unit which would be caused by the same problem – this problem usually only shows itself when the weather is really cold and the meter regulator does not react to the demand request fast enough. A similar problem can be the result of undersized gas piping but if this were the case then problem would be there everytime you tried to start both the water heater and the central heating unit at the same time. I really suspect the meter set is your fault – particulary we are now into the winter cooler months where meter diaphrams often fail due to the outside air temps.
Have the check done and let me know the outcome please.

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Selgas Services Ltd
Craftsman Gasfitters, Plumbers, Electrical Service Technicians

[jkobierParticipant]

Apologies for the delay in getting baack to you. BAsically the problem is not resolved and we have done the following:

-Cleaned water filter in unit – wasn’t actually dirty.

-Checked Gas pressure – according to the gas authority gas pressure is more than adequate and has a new regulator.

-Tried insulating the regulator, theory being to prevent it getting to cold over night therefore the rubber diaphragm will remain flexible – even tried heating it up with a heat bag! No luck on both accounts!

Spoken with Rinnai who suggested that his was a known issue with the older (8 years old) units but the phone got cut off after being on hold for 30mins and when I called back no one knew what I was talking about.

We have had 2 technicans look at it and gas pressure checked 3 times, it is getting to the stage where it will be cheaper to replace the whole unit.

Starting to give me the SH*TS!!

Any more suggestions greatly appreciated.

[SelgasParticipant]

Just a further suggestion here have you had the shower mixer checked to make sure it’s internals are all ok and not worn where a similar problem could be the result.
I am a Rinnai Service Agent and I can assure you I have never heard of such a problem being with the earlier units of 8 years age. If everything is set up correctly and the gas pressures are correctly set, the water flow is correct and the gas supply from the meter is sized correctly – the only other factor would be a faulty or worn shower mixer. Have it checked out – let me know the outcome please.

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Selgas Services Ltd
Craftsman Gasfitters, Plumbers, Electrical Service Technicians

[tcp1830Participant]

If you haven’t solved the problem by now looks like its been a few months since your post. Temp flux can be corrected by adjusting the dip switches for your altitude

[tcp1830Participant]

For those of you with rinnai problems I have a few answers to common problems loud vitbrations cause by blockage of vent/ combustion part of vent, bugs or moisture in combustion fan, clean and install condensate drian (even on horizontal vent installations deeping on where u are wind rain snow. Also check vent conections if vent isn’t connected properly unit will try to burn its own exhaust and vibrated loudly. If you are haveing trouble with unit not heating consistently try adjusting your dip swithches for your alititude, of couse also check gas presure, filters, crossed water lines basic stuff. Newest problem with vibrating unit when washer and another fixture was running at same time was solved by installing hammer arresters on washer box connections. Any new Questions feel free to ask Ive Only Installed about 150 of these. Hope I helped

[SelgasParticipant]

Newby

Thank you for your valued input it is appreciated however, in this persons case the fluctuation in water temps is most always due to the high and low flame settings not being correctly set ( yes I know there are other likely causes but I like you have only been a service agent for around 20 years and have repaired and resolved many hundreds of these problems). I have found that providing there is sufficient gas pressure to the unit and, the high and low settings are correctly adjusted and, there is at least 4 litres of pure hot water flowing the problem does not usually arrise.

However, in saying this there will always be the one in a thousand that gives unusual symptoms and problems that can really only be resolved by a service agent being on the job at the location and testing everything to eliminate things such as you have pointed out.

I might add that the problem of fluctuating temps has mostly been found on the unflued versions rather than the connected flued ones for some strange reason.

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