# Rinnai strange behavior



## futz (Sep 17, 2009)

So, a brand new Rinnai RU98i. Go for first fireup and... Error 11. Over and over - Error 11. I pop the cover and give it a once over. Check the spark - fine. Hmm... Purge the gas line - pressure is fine and gas is there. Try again, and it lights off and works fine the rest of the day. OK, probably just a bit of air in the gas line.

Next day the GC calls and it's Error 11's again. I head over and threaten the thing with tools. I put a manometer on the gas test port and the reg is set at 9" - a bit higher than it should be. Without changing that I test fire again and it fires right up. So I adjust that down a bit to 7" and... it continues to work the rest of the day. Great!

Next day the GC calls again. Same problem. By this time I have a theory in my head. I walk in and verify that it's still throwing Error 11's. It is. I partially unscrew the gas test port and let it hiss for a few seconds. Then I try firing it. It fires right up and works perfect.

Has to be the gas reg, so I call the gasfitter and ask him to change out the reg. He doesn't believe me at all, but I finally talk him into changing it. It's been fine ever since. Victory is mine! :thumbup:

I'm not a huge gas reg expert, but my theory is that the reg wasn't locking up properly (maybe something in it) and the finnicky Rinnai gas valve doesn't like opening against 2 lb. gas. I guess it takes several hours (overnight) for it to creep up to 2 lb., so I'd get a call every day when someone first tried to get hot water.


----------



## Cal (Jun 17, 2008)

2 psi direct into unit regulator ?? Oh no .


----------



## futz (Sep 17, 2009)

Cal said:


> 2 psi direct into unit regulator ?? Oh no .


Huh? No! That would be stupid, illegal and probably dangerous. 

The house lines are at 2 PSI. Then there's a 7" reg that feeds the connector to the Rinnai.


----------



## Cal (Jun 17, 2008)

Oh ok . Whew !! Read it wrong .


----------



## s.ford (Mar 19, 2014)

Put your manometer on and hit the relief valve and fire it up if it drops more than 20th still not fixed odds are its not the reg


----------



## s.ford (Mar 19, 2014)

2" sorry


----------



## plbgbiz (Aug 27, 2010)

s.ford said:


> 2" sorry



PZ is a site for those already in the plumbing trade. You are welcome to view the site and use the information available to you. Please refrain from posting until you have established that you are active in the trade. 

Start here>>> http://www.plumbingzone.com/f3/


Thanks.


----------



## s.ford (Mar 19, 2014)

Lol been in the trade bout ad long as old u are............


----------



## plbgbiz (Aug 27, 2010)

s.ford said:


> Lol been in the trade bout ad long as old u are............


Then your next post will no doubt be an intro so we can all welcome you and benefit from your experience.


----------



## plumbdrum (Nov 30, 2013)

In Ma you cannot run elevated gas pressures over 14" wc or 1/2 psi without prior special permission from our state board. Those pressures are usually found on larger commercial jobs, never residential. If your piping is sized properly why would you want the liability of those pressures in a building with regulators?

Sent from my iPhone using PlumbingZone


----------



## futz (Sep 17, 2009)

plumbdrum said:


> In Ma you cannot run elevated gas pressures over 14" wc or 1/2 psi without prior special permission from our state board. Those pressures are usually found on larger commercial jobs, never residential. If your piping is sized properly why would you want the liability of those pressures in a building with regulators?


Hmm... Well, I don't live in MA. We've had 2 pound gas here in B.C. for many decades. It works pretty well. I can't remember ever having any failures, and I've been at this a long time.

I remember when I was a young fitter we could get 5 pound gas in commercial. I think they've changed that to 2 pound now, but I could be wrong.

I'm pretty much out of the gasfitting business now. I can barely keep up with plumbing and hot water heating. Still licensed and still have my power vise (clogging up my tiny shop), but not really doing much gasfitting anymore. I push all but the smallest gasfitting requests to a quality local fitter that I get along with well.


----------



## futz (Sep 17, 2009)

s.ford said:


> Put your manometer on and hit the relief valve and fire it up if it drops more than 2" still not fixed odds are its not the reg


It was definitely the reg. I've had zero callbacks on it since the reg replacement. The new owners have been moved in for... what... a month now? It's cured.

I remember pressure dropping just about an inch on fire up when I tested it. Well within spec.


----------



## plumbdrum (Nov 30, 2013)

futz said:


> Hmm... Well, I don't live in MA. We've had 2 pound gas here in B.C. for many decades. It works pretty well. I can't remember ever having any failures, and I've been at this a long time. I remember when I was a young fitter we could get 5 pound gas in commercial. I think they've changed that to 2 pound now, but I could be wrong. I'm pretty much out of the gasfitting business now. I can barely keep up with plumbing and hot water heating. Still licensed and still have my power vise (clogging up my tiny shop), but not really doing much gasfitting anymore. I push all but the smallest gasfitting requests to a quality local fitter that I get along with well.


We have pounds , but for the most part it's not needed in almost every case. If the piping is sized correctly , 1/2 psi is all that's needed. Eliminates the need for regulators in every piece of equipment which can get expensive . If pounds are needed, it needs to be Engineered and presented to the State with a special permission application for approval. That's the way it happens here and I'm happy for that.

Sent from my iPhone using PlumbingZone


----------



## CaberTosser (Mar 7, 2013)

There's lots of residential condominiums with higher pressure gas where I am; on towers its regulated down at each floor (eg: gas fireplaces and kitchen ranges), or on the very long/wide buildings its regulated down in zones. I'm also aware of some towers where each suite has a small Baxi boiler to take care of both its domestic hot water needs as well as their space heating through baseboard radiators. I've seen some townhouse condo's set up like this as well. These struck me as excellent spots to market my services, as they'll all need descaling and repairs and the unit owners are responsible for getting it done themselves rather than the condo management. In the large towers I'm wondering what their central mechanical room looks like because 80%+ has its own heat source, it would probably appear rather undersized for the building at first glance. The condo management only have to heat the common areas and the parkade, so it takes some responsibility off their shoulders.


----------



## BC73RS (Jan 25, 2014)

The craziest gas fitting I experienced was a vertical metering system where in a tower each suite had it's own gas meter. The riser was 5 psi. The customer could any gas appliance they wanted as it was piped in 1" at 14". The meters were crammed in a central closet every third floor. 
The mechanical room on the roof had it's own riser at 5 psi.


----------



## plumbdrum (Nov 30, 2013)

BC73RS said:


> The craziest gas fitting I experienced was a vertical metering system where in a tower each suite had it's own gas meter. The riser was 5 psi. The customer could any gas appliance they wanted as it was piped in 1" at 14". The meters were crammed in a central closet every third floor. The mechanical room on the roof had it's own riser at 5 psi.


Ok, here's crazy. Just did an inspection with my fellow inspector a couple of months back on a LNG filling station. 44 psi out of the meter into a gas compressor to 3,400 psi. Engineered project to fill trash trucks with LNG. Very interesting project.

Sent from my iPhone using PlumbingZone


----------



## futz (Sep 17, 2009)

Had another one today. Same exact thing with the new (few weeks old) Rinnai and Error 11s. The gas reg wouldn't lock up - this one was worse than the first one which took overnight to get up to too high of pressure for the Rinnai gas valve to open.

On this one I hooked up my manometer and watched as the pressure steadily rose until, still climbing, it pinned the needle at 16+ inches. At the rate it was going it'd be at 2 PSI in a few minutes.

I gave the reg a good beating with a wrench while the tankless was running, hoping to knock loose whatever might be stuck in it. Didn't help. Finally I called the gasfitter and had him come out to replace his regulator.


----------



## Dpeckplb (Sep 20, 2013)

We've had faulty regs lately too. I'm wondering if they are using weaker springs.


----------



## dhal22 (Jul 30, 2010)

futz said:


> So, a brand new Rinnai RU98i. Go for first fireup and... Error 11. Over and over - Error 11. I pop the cover and give it a once over. Check the spark - fine. Hmm... Purge the gas line - pressure is fine and gas is there. Try again, and it lights off and works fine the rest of the day. OK, probably just a bit of air in the gas line.
> 
> Next day the GC calls and it's Error 11's again. I head over and threaten the thing with tools. I put a manometer on the gas test port and the reg is set at 9" - a bit higher than it should be. Without changing that I test fire again and it fires right up. So I adjust that down a bit to 7" and... it continues to work the rest of the day. Great!
> 
> ...


We've installed 4 of these recently. Error code 11's on each of them. I need to find out what the solution was.


----------



## Otobeme (Jul 9, 2015)

plumbdrum said:


> In Ma you cannot run elevated gas pressures over 14" wc or 1/2 psi without prior special permission from our state board. Those pressures are usually found on larger commercial jobs, never residential. If your piping is sized properly why would you want the liability of those pressures in a building with regulators?
> 
> Sent from my iPhone using PlumbingZone


1.5 - 2 million btu's in a home, stretched out a few hundred feet is not uncommon. Have to have 2psi. Never heard of a problem or liability issue. One call to the gas company and it's done, really easy. 
In an existing home where you cannot get back to the meter with a line and they are adding onto the house, have the gas company install a 2psi gas regulator on the meter, regulate the existing appliances, find a tie in somewhere for new appliances. Very convenient and cost effective.


----------



## joeplumber85 (Jul 16, 2012)

futz said:


> Had another one today. Same exact thing with the new (few weeks old) Rinnai and Error 11s. The gas reg wouldn't lock up - this one was worse than the first one which took overnight to get up to too high of pressure for the Rinnai gas valve to open.
> 
> On this one I hooked up my manometer and watched as the pressure steadily rose until, still climbing, it pinned the needle at 16+ inches. At the rate it was going it'd be at 2 PSI in a few minutes.
> 
> I gave the reg a good beating with a wrench while the tankless was running, hoping to knock loose whatever might be stuck in it. Didn't help. Finally I called the gasfitter and had him come out to replace his regulator.



How much piping between regulator & Rinnai? If it's not at least 6-8 feet of 3/4" inch, that might be your problem.


----------

