Tachypsychia 13 Posted January 13, 2014 Share Posted January 13, 2014 Hey guys, I'm kind of stumped and I don't like to be stumped. (For cliff notes skip to the bottom) First of all I live in Aomori, and in the last few days its been nice and cold. Temperatures have finally dipped well below 0, reaching -9 during the night. The wife and I have not had a winter in Japan yet so this is our first. All the other water lines are fine, as we make sure to run water through them often, but the tankless water heater for our bath has frozen 3 times despite my best efforts. I thought that our lines had busted from freezing. Because the government owns our housing, we have to contact them for everything we need housing wise. If we need a lightbulb changed, we have to call someone to put us on a list and wait a few days for someone to come by and replace our bulb. Now because we're out of a hot shower, it's an immediate concern of mine, and given that they'll charge us 30,000Y just to come out and look at it, I'd rather see what's going on myself. I was an electrical technician back home and in the military so I am big into repairing things on my own if I can, and while I'm ok on HVAC/ small scale electronics, Gas heaters are a territory I haven't had a chance to venture in yet. The model in question is a Rinnai RBF-ASBK-FX-L-T. I have yet to find much in the way of service manuals so I just took the whole thing apart in the bathroom to figure it out (after I turned the gas and water off of course). So it seems like the reason that it's freezing is because the exhaust of the heater is exposed to outside air, constantly. Literally theres a chute that goes outside and has some thin metal to vent outside. When its cold, the air can go directly to the radiator portion, and if there's any water in the lines it will freeze. To get past that part, they showed us how to drain the water out of the lines, which we did. But apparently we aren't leaking all of the water out, because SOMETHING is still freezing in it, and when I go to run water through, the flow control valve (controls how much water from the tap gets heated at once, also controlling water temp) gets stuck, as well as the drain valve, even when it is fully open to let water out. I took it all apart and when I got the lines unfrozen with a space heater, I ran water to the heater with no valves open to check for leaks. So it leaks from every fitting that's in there. I couldn't find any actual busted pipe lines. I assumed that the extreme cold is contracting the metal and the o-rings aren't sufficient enough. I tightened all the connections more, and turned the water on again. Everything held pressure without issue. Ok great, problem solved right? We'll by the time I put everything back together and turned the gas back on (35 minutes?) it had refrozen somewhere and the lines started leaking AGAIN. I have yet to take it apart again, and just left it with the water drained. We can use the recirculation to heat up bath water ok, but if we want to get HOT water out of the shower, then its near impossible. I've managed to get the flow just right so that the shower works, but because the lines leak, after a while, the burners just shut off due to water build up. Of course this is unsafe and hard to do. Before I get a japanese repair man involved and throw some money at this, I wanted some advice from those with similar setups living in Japan. Because the heat coils/pipes are constantly explosed to outside air, how the hell am I supposed to insulate it or keep the water from freezing? Am I draining it right? Our board of education is no help, as we've already checked with them to make sure we're doing the procedure right, but they just say to call a repair man. I don't know how our other neighbors don't have this issue as we all have the same exact setup. Cliff notes: Water heater keeps freezing, even when water is drained. How do we stop that? Any advice from others with tankless gas water heaters living in cold regions? Link to post Share on other sites
Metabo Oyaji 71 Posted January 13, 2014 Share Posted January 13, 2014 Is there any way you can blow air through the water pipes after draining to make sure it is all drained? Alternatively, is there some way you can seal off the exhaust port when it is off so that cold air does not come back in? (Dangerous if you were to leave it blocked when you turned it on, though!) By the way, googling "Rinnai RBF-ASBK-FX-L-T" turns up this service notice: 風呂釜の内部でガス漏れが発生するおそれがある 2011年6月22日 【不具合内容】 リンナイ株式会社は、株式会社ガスターが製造し同社が販売した下記のガスバランス型風呂釜において、部品の不良により風呂釜内部でガス漏れが発生するおそれがあるとして、対象製品の部品交換を行うと発表した。 [...] 製品名：RBF-ASBK-FX-L-T ガス種：都市ガス、LPガス 製品番号：11.02-000503～11.05-006771、11.02-000197～11.05-002903 Might want to check your serial number and see if it is one of the affected units. Link to post Share on other sites
Chriselle 158 Posted January 13, 2014 Share Posted January 13, 2014 Hmm...perplexing. I have done a bit of maintenance on our very old and tired unit but we aren't in cold country. Logic tell me there is something wrong with your unit because at those temps (not so extreme) the built in "antifreeze" circuit or backdraft damper should be sufficient especially being located inside. If that's the way it is going to be though I would think about reducing the backdraft by either building a better vent hood or making the exhaust run longer and insulating the shit out of every inch of that pipe. AND....investing in an exchanger freeze protection kit for $50 or so.... Link to post Share on other sites
Tachypsychia 13 Posted January 13, 2014 Author Share Posted January 13, 2014 Thanks for the input guys. I took it apart again today and reconnected the water. The joints I re-tightened the other day are fine. Unfortunately there is a small crack in the pipe on one of the coils. Its not on one of the easily removed lines, but the heater coil for the shower/hot water tap. I have yet to remove because I don't know if they have JB weld or an equivalent epoxy here I can use. Since the repair money would have to come out of pocket here, I'd like to try and band aid it until later. Chances are they'll want us to get a new heater entirely which are ￥￥￥. I'll also check my model number to see about that gas leak recall. I looked outside and didn't see anyway to curb the venting to outside. I removed the exhaust hood again and man its like being right outside. I'm trying to read the service manual I found online but my kanji recognition sucks and I can't see anything specific about freeze protection yet. There's a Sunday nearby me but I don't know if they'd carry anything I can use. Ideas? Link to post Share on other sites
Tachypsychia 13 Posted January 13, 2014 Author Share Posted January 13, 2014 Went to Sunday and got this: Not sure if its for use with plumbing, but its not like its for potable water... Link to post Share on other sites
Chriselle 158 Posted January 13, 2014 Share Posted January 13, 2014 I bought JB Weld on Rakuten. http://item.rakuten.co.jp/todakana/0043425826558/ Sounds like the install contractor should be shot with a ball of his own shit...!! Maybe post a picture or two of the exhaust vent. Look into the Bosch freeze protection kit. Link to post Share on other sites
pie-eater 207 Posted January 13, 2014 Share Posted January 13, 2014 What is 'Sunday'? Link to post Share on other sites
Metabo Oyaji 71 Posted January 13, 2014 Share Posted January 13, 2014 Some kind of home center, presumably. I see from their manual that "chimney"-style outlets are acceptable. I imagine that convection might lead to air being drawn from the inside of the house to the outside in that case, which would reduce freezing problems. I also imagine that if you are in government housing, there is squat-all you can do about that, unfortunately. Link to post Share on other sites
Tachypsychia 13 Posted January 13, 2014 Author Share Posted January 13, 2014 Just finished putting on the epoxy. Going to let it cure near the heater for a full 24 hours before I put everything back together. It's too late for me to bother putting it all back together anyway. If it doesn't work, I'll at least see if I can get a new radiator coil. Sorry, Sunday is the local home improvement store in my prefecture. This is the crack before I sealed it. And here's a shot of my exhaust. So where you see the heater coils is where the hood sits, just some thin aluminum. Then goes straight outside. The vent protrudes 1 foot or so outside. And its that same thin metal. So like no insulation. I also don't think this model has any kind of freeze prevention circulation. Far as I can tell, it just wants you to drain the water every time you're done using in cold weather. I can't copy the japanese from the PDF into a translator. What a pain. But the instructions visually seem easy enough. Edit- Sorry the instructions are so small. They were full size when I originally linked it? Thanks for the JB weld link! I will definitely search for the freeze protection kit. This has been such a headache, but a good excuse to go to onsen to shower. Link to post Share on other sites
Tubby Beaver 209 Posted January 13, 2014 Share Posted January 13, 2014 welcome to crazily old, cold and shitty Japanese housing!! Hope you get it fixed cos when its cold, not having hot water is a bitch!! Link to post Share on other sites
Chriselle 158 Posted January 13, 2014 Share Posted January 13, 2014 Ya...that is bullshit building right there. When you get it up and running again let it go for a full cycle...a hot bath....and check in the vent to see which parts are getting hot. Anything that isn't ... insulate it. Depending where your bathroom light is you could also splice a run of romex and mount a light bulb socket in there and leave a 100 watt incandescent or flood light on at night....It's only for another month or two. ... That's a pretty hefty crack for an epoxy.... Worth a shot though.... I'd pinch the crack back together and braze it with silver solder and THEN epoxy it... ...but see how the epoxy patch holds first. Link to post Share on other sites
Tachypsychia 13 Posted January 14, 2014 Author Share Posted January 14, 2014 Thanks for the advice Chriselle. I was literally stunned when I first saw how it vented. The water pressure is pretty weak, so I feel pretty confident it'll be ok. I'll throw everything back together tonight and cross my fingers! I'll update either way. Link to post Share on other sites
Tachypsychia 13 Posted January 15, 2014 Author Share Posted January 15, 2014 I let the epoxy resin cure 24 hours then put everything back together. It didn't work at first (OMFMWTF) because the gas line was frozen. I had to heat up the pipes to get enough fuel to ignite the burners. But everything checks out and I took a nice hot shower as a victory lap. I also never bothered to open the plastic bag under the cover because I thought it had warranty information in it. Turns out Rinnai included a TON of schematics for the electronics as well as a exploded view of every part on the heater. It would have helped immensely taking everything apart if I had looked at it first instead of learning as I went. Oh well. Hope it lasts a while... Link to post Share on other sites
Chriselle 158 Posted January 15, 2014 Share Posted January 15, 2014 Now you just have to concern yourself with keeping it thawed.... Link to post Share on other sites
Tubby Beaver 209 Posted January 15, 2014 Share Posted January 15, 2014 Good save tho Link to post Share on other sites
Chriselle 158 Posted January 15, 2014 Share Posted January 15, 2014 Oh yes......bravo!! Link to post Share on other sites
muikabochi 208 Posted January 16, 2014 Share Posted January 16, 2014 At least Dawson isn't crying today! Link to post Share on other sites
Chriselle 158 Posted January 16, 2014 Share Posted January 16, 2014 ...Pies favorite gif... Link to post Share on other sites
Tachypsychia 13 Posted January 16, 2014 Author Share Posted January 16, 2014 Three showers.. two baths. No explosions.... Link to post Share on other sites
Chriselle 158 Posted January 16, 2014 Share Posted January 16, 2014 :thumbsup: Link to post Share on other sites
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