Hello welcome back to the grand compound thanks for checking out my channel hopefully you guys have just seen the part 1 of tankless water heater problems and you already realize that if they were installed correctly you should have no tankless water heater problems if you haven’t watched the first part yet please go back and watch that first that’s going to take care of 95% 99% of the problems out there with tankless water heaters other than that I realized things age things break things fail things happen,
So I’m going to go through some of the more common tankless water heater problems which are not that common but are things that you may run into with your tankless water year after a few years and whatnot so stick with me and we’re going to go right into a few things now and most of these are very simple you’ll kind of get the idea here in a minute alright the first thing I want to get into and before I do don’t forget to hit that like button right down there actually I think it’s over here hit the thumbs up like button subscribe to my channel now the first thing I want to talk to you about is something that is specific to tankless water heaters and that is a cold water sandwich and that is a phenomenon that happens basically when you have run hot water all of your pipes in the house are full of hot water the tankless water heater runs and then you stop using hot water tanks water heater goes into a post purge or a cool-down mode and it will pre cool the heat exchanger in the water heater lower the temperature your pipes however are still full of hot water.
So if someone comes in and hops in the shower five or 10 minutes later they may turn on the water and have hot water instantly because the pipes are full of hot water but the first slug of water out of these machines is not hot takes about four seconds for one of these things to fire up and give you some point temperature and this by the way is not brand specific this is pretty much everybody alright if you don’t have some kind of storage tank which quite frankly I don’t think you want or need you’re going to get a little cold water sandwich in that specific instance so what happens is for the first four seconds you’ve hopped in the shower you have hot water pipes you’re full of hot water 4 seconds cold water the tankless water heater and in a minute or two you get a little surprise in the shower because the temperature dips down and then goes right back up and stabilizes again typically what happens you get in the shower you set the temperature you like you get in feels good and then you start after a minute or two the temperature drops and it’s not comfortable you move out of the way and then.
It comes back and it’s hotter and you have to mix them or cold waters you actually get three water temperatures the reason is you’re bringing the tempered water that has been cooling in the pipes first that’s what you set your temperature by then you get a few seconds of cold water Sandwich that hits you which is typically 10 degrees or so less than the other temperature which is not comfortable and then it comes back full bore hot and you have to reset it this is not a super common occurrence but it’s not exactly super rare either and it’s only when you have used hot water there’s been a lag time in between years in the hot water relatively short a few minutes 10 minutes or so and then use hot water again that’s a cold water sandwich once you understand that may not be a big problem if it is a problem for you there are ways around it call your certified authorized service provider your installer your dealer you did have this installed professionally right if you didn’t eat stop watching this part right now go back read or see part number one there is basin you if you didn’t have this installed by professional everything you’re watching here is probably not your problem.
It’s probably an installation issue that’s cold water sandwich in a nutshell and hope that have some some questions there and we’ll move on to the next point ok now I’m going to get into some specific error codes most of the major tankless water heater brands use the same error codes 10 11 12 14 these are all codes 61 that are not brand specific most I don’t know if the engineers have moved from one manufacturer to another they pretty much all use the same code first off code 11 code 11 tells you most cases the unit tried to light and it could not like in that case chances already have some kind of gas issue going on and the unit is not lighting could be a vent issue it’s not like either way time to call a professional in on this thing okay did you pay your gas bill is your propane tank out of gas or running very very low even one of these can cause those problems a code 10 is almost always a venting problem a combustion air problem the unit is developing back pressure check for birdsnest wasp nest did you have your house painted – the painter tape a plastic bag over the vent termination it can’t suck air in fresh air those are the kind of things that causing code 10 the vent pipe having separated partially can cause a code 10 maybe you had sorry.
I have to keep doing this but maybe had a flunkey install it he installed the wrong vent pipe and that’s why you’re getting a code 10 code tens are almost always combustion air or venting relief so that’s 11 in 10 next we’re going to move on to code 12 all right code 12 was actually one of my favorite and the reason why is because it’s so much fun when someone calls you that’s a plumber or an HVAC service tech they say have a code 12 on my tankless water heater and I asked them okay what’s your gas pressure they got oh I got a ton of gas I got playing gas I got lots of gas that’s not a number what is your gas pressure code 12 is very often a gas pressure problem again is your propane tank running low have you paid your gas bill did you have a regulator failure just because the heater ran for three years that’s been fine for three years doesn’t mean it’s running fine today what your gas pressure was three years ago doesn’t mean it’s correct right now you have to take a reading with a very specific tool called a manometer most people are not going to own one unless they’re in the trade and most of people in the trade don’t own one which is unfortunate.
If you’re going to work on these kinds of machines or any of the high efficiency high-tech stuff you need a manometer and you need to know how to use it so that’s going to be where we’re going to go with that first code 12 can also be an electrical problem a bad ground a short inside the unit if you had a lightning strike something got fried inside causing a short-circuit that can give you code 12 a really good thing to know is listen to the water heat of fire if you hear the water heater startup and you hear the poof of the gas igniting and then it goes to code 12 you have a gas problem if you don’t hear to proof if you hear the fan come on it go straight to code 12 before it lights you probably have an electrical problem going on and again you’re right back to having a trained authorized service provider work on these pieces of equipment so you’re going to find that as a common theme with this part of the video but I’m giving you specifics on what these problems are and again this is over hundreds of thousands of units and many hundreds of service calls not something you’re going to see regularly but things that can happen so that’s code 12.