Our Rinnai unit

Forums › Home Workshop DIY › Our Rinnai unit - faulty

rayonline

1734 posts

Uber Geek

#231966 23-Mar-2018 09:18

Woke up no hot water. Turned the wall temperature unit panel on and off and on and off at the power meter box. Then suddenly with the wall unit turned off there was hot water but there is white steam coming out of the Rinnai unit. Before turning it off, the temperature read out would fluctuate up to 61 degrees and no hot water would come out.

We need this to be looked at obviously. We also bought an extra unit some yrs ago when I got this fitted. So you think it is worthy to be looked at and repaired or get them to swap in a new unit? This is the instant hot water with pipped gas (natural gas).

Cheers.

JayADee

2118 posts

Uber Geek

#1981992 23-Mar-2018 11:50

Ask the guy who comes to fix it. We had our old one fixed, didn't cost much and it went on to live quite a while after that. Then a few years ago (after about twelve years total, maybe longer) we had the repair guy out to see if we could increase the temp. as it wasn't getting as hot as we'd like anymore. No, for some reason, so we had it replaced with a new one.

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rayonline

1734 posts

Uber Geek

#1982316 23-Mar-2018 17:38

Ok .. so it is Friday. Looking online for reviews. One won't be able to come till Monday and asked us to look for someone else. Someone else did come over. They opened up the unit and didn't say what has to be done and then said the gas pipe was not the right size and looked around our home. We were told nothing can be done right now and sometime next week and he will redo another visit with the boss to see what the solution can be.

The previous owner had cylinder gas hot water with electrical cooking. There is a gas heater in the lounge and some floor gas taps but we don't use them - thickness etc ... dunno the house is what we bought it. When the cylinder broke we switched to instant gas (Rinnai) this was like 12yrs ago. And sometime after that we switched the oven cook top to gas.

So ... do we need to get all the pipes replaced under and house and behind the walls or do we switch the oven back to electric and the water back to cylinder ...

sparkz25

750 posts

Ultimate Geek
Inactive user

#1982319 23-Mar-2018 17:48

can you check the size of the pipe your self, i would thing that a 20-25mm pipe would be sufficent to supply the infinity and or the gas hob, i know i have a 25mm to the infinity then the last 1m is reduced to 15mm for the hobs, and we dont have any problems at all.

personally i wouldnt go back to a electric cook top of any form, gas is so much better!

cryan209

18 posts

Geek

ID Verified

#1982320 23-Mar-2018 17:53

If the controller flashes 61 when its in use that indicates a failure to the combustion fan motor - page 21 here: https://rinnai.co.nz/Download/ProductFile?encid=S7qWo6EfENACk68hBhvuBP_XBQG9FVlvn5r9VZJ5sAo~ has a list of error codes

rayonline

1734 posts

Uber Geek

#1982324 23-Mar-2018 18:01

Thanks for that error code.

I took a tape measure out. The brand new pipe 12yrs ago coming straight off the Rinnai Infinity is 15mm. The previous owner who have a pipe that goes upstairs for the floor gas taps is also 15mm.

Aredwood

3885 posts

Uber Geek

#1982407 24-Mar-2018 02:01

@rayonline Your infinity has a small heat exchanger water leak. The fan is underneath the heat exchanger and burners. So you get either code 61, or codes 11 or 12. (Ignition failure and flame went out when it shouldn't).

All of the white steam is the water getting evaporated out of the heat exchanger and burners when you do manage to get it to start. Definitely needs replacement.

The gas pipes of that age should have been sized to NZS 5261 2003 (depending on the installation date of course). Since you said you have 12M of 15mm gas pipe, If we assume best case scenario (3kpa pressure at the meter, and the infinity being the only gas appliance). That pipework would have been rated to max of around 60MJ/Hr. A domestic gas hot water cylinder draws around 20 to 35MJ/Hr (depending on model). But the early Rinnai Infinity 20 draws 188MJ/Hr - Fail.

So that Gasfitting company are definitely right to say that your gas pipes need upgrading if you want to get another Infinity. Assuming that you can run a new pipe from the meter to the Infinity, this would probably be the cheapest way to make the pipe system compliant. As assuming your gas cooker is the typical 4 burner with electric oven, then approx 35MJ/Hr for that, and 23MJ/Hr for a bayonet point (floor gas tap). Your remaining 15mm pipe would probably be compliant (or at least close enough for an existing installation). Bearing in mind that an undersized pipe to a cooker simply means that you don't quite get full heat when all burners are on max. (And in most domestic installations you could apply a diversity factor to a cooker anyway) Which although annoying is not enough of a hazard to require upgrading of pipework. But Infinities on the other hand, have a fan forced burner design. For them to work properly, they need the correct amount of gas to match the air that the fan is blowing in. Incorrect gas pipe sizing to an Infinity causes things like the exhaust smelling "gassy", Spurious fault codes, unstable outlet temperature.

Definitely important to get the pipe sizing right.

rayonline

1734 posts

Uber Geek

#1982435 24-Mar-2018 09:26

The job might be too large then.

The gas meter is on the right side of the house. The previous gas cylinder hot water is on the left side (now the Rinnai unit). So I guess the gas pipe is either from one side of the house to the other side under the front door entrance and garage or it is under the first floor of the lounge / dining area.

jonathan18

7413 posts

Uber Geek

ID Verified

Trusted

#1982460 24-Mar-2018 10:09

Aredwood:

But Infinities on the other hand, have a fan forced burner design. For them to work properly, they need the correct amount of gas to match the air that the fan is blowing in. Incorrect gas pipe sizing to an Infinity causes things like the exhaust smelling "gassy", Spurious fault codes, unstable outlet temperature.

Definitely important to get the pipe sizing right.

Sorry for the threadcr@p but, @Aredwood, your post made me concerned about our own Rinnai install. We get a decently gassy smell emitting from the unit each time it's used. We've had no other issues with its operation since its install, and it's been way cheaper to run than the old gas cylinder, but reading this made me think something could be up. I recall they replaced the pipework from the meter to the Rinnai (assuming for the same reasons you mentioned here), so I'm not sure what the story could be - any ideas?! Thanks...

rayonline

1734 posts

Uber Geek

#1982547 24-Mar-2018 14:21

Had a look at the pipes. Water heater left of house. Gas meter on the right side. Gas pipe goes in ceiling of the garage and then maybe between the ground and first floor to the gas meter but the previous owner put in a Conservatory extension build just above the gas meter so the pipe is maybe under tile flooring. They also put in a gas heater in the lounge and a gas tap in the lounge and in the dining room, also there is a gas pipe that runs under the house / under patio to the back where they have a BBQ.

Dratsab

3946 posts

Uber Geek

Trusted

Lifetime subscriber

#1982552 24-Mar-2018 14:42

Does sound like it could be a big job but then again - I have no idea what I'm talking about here. I'd suggest not worrying about anything until the people that know what they're doing come in, inspect it, and give you the full rundown. Things may not be as bad as they seem and they may have ways of doing jobs like this that make things a little easier than you might think. Out of interest, are the pipes coming off the meter 15mm? If not, at what point do they seem to reduce?

rayonline

1734 posts

Uber Geek

#1982556 24-Mar-2018 14:46

The pipes out of the meter running up the wall and those on the garages ceiling are 15mm.

Aredwood

3885 posts

Uber Geek

#1982582 24-Mar-2018 16:34

jonathan18:
Aredwood:

But Infinities on the other hand, have a fan forced burner design. For them to work properly, they need the correct amount of gas to match the air that the fan is blowing in. Incorrect gas pipe sizing to an Infinity causes things like the exhaust smelling "gassy", Spurious fault codes, unstable outlet temperature.

Definitely important to get the pipe sizing right.

Sorry for the threadcr@p but, @Aredwood, your post made me concerned about our own Rinnai install. We get a decently gassy smell emitting from the unit each time it's used. We've had no other issues with its operation since its install, and it's been way cheaper to run than the old gas cylinder, but reading this made me think something could be up. I recall they replaced the pipework from the meter to the Rinnai (assuming for the same reasons you mentioned here), so I'm not sure what the story could be - any ideas?! Thanks...

Your unit just probably needs to be re commissioned. Involves adjusting internal gas pressure settings.

Aredwood

3885 posts

Uber Geek

#1982583 24-Mar-2018 16:40

rayonline:
Had a look at the pipes. Water heater left of house. Gas meter on the right side. Gas pipe goes in ceiling of the garage and then maybe between the ground and first floor to the gas meter but the previous owner put in a Conservatory extension build just above the gas meter so the pipe is maybe under tile flooring. They also put in a gas heater in the lounge and a gas tap in the lounge and in the dining room, also there is a gas pipe that runs under the house / under patio to the back where they have a BBQ.

Looks like you will have to get a gas hot water cylinder instead of a new infinity. Assuming a method can't be found to run new gas pipes. If you do get a gas hot water cylinder, get the Rheem Stellar. As they are a condensing water heater. Therefore a lot more efficient than the old style internal gas hot water cylinders.