Hot water systems
 

Out current hot water tank is being annoying (sometimes the water is only warm, and if someone takes a long shower it runs out) and it's nearing EOL so we're looking at different options for a replacement. We're planning to be in this house another 20+ years if life goes well so long term life expectancy vs cost is a factor.

Our current system is gas, from my understanding the options are a regular tank system, a condensing tank system and a condensing tankless system. I'm leaning towards a condensing tankless system for the long lifespan, gas savings and not having a big tank waiting to flood the basement when it fails. My wifes main concern is if they're capable of handling something like two people showering at the same time. When I was a kid I showered last and always ended up cold, now that I own the place I don't want to be doing the same once I have teenagers.

Thoughts? Experiences? Do tankless really last as long as expected? Can they keep up with a busy family of 4?

I had considered a tankless system when our original tank was EOL (in fact, it died) so I had explored the options you mentioned, and went with another regular hot water tank.

One of the reasons was that the tankless system (at the time) was very expensive, so the cost to benefit ratio for our purposes was not appealing. On the flip side, the energy savings was worth it, but we weren't looking to keep the house forever, or rather, we had planned to renovate it through and through. The cheapest option for us was the regular tank, and it's been fine for us so far. We over extended the life span of our original hot water tank, but it also goes to show that it lasted 14 years trouble free. But when it went, it went hard haha.

I think a tankless system should work in your situation. I know much bigger families of 8 who use one and are fine with it. They often take showers back to back, or someone is showering, and another parent is bathing their child or toddler etc. Longevity seems to be okay as they've lived in the house using the same tankless system for over 5+ years, and it has served 8+ people. Hopefully others can chime in as I'm not sure whether this is the norm, or the exception.

I looked into the same issue as the OP did last year, and for my application, despite us planning our place to be our forever home in the foreseeable future, we opted to stick with the good ol' tried and true water tank.

My plumber was someone my family knows, so I don't think he was trying to upsell us. He was a very big proponent of the new tankless system due to the higher efficiency (therefore theoretical lower long term costs) and the benefit of "never running out of hot water". Obviously, the initial setup costs were higher, and unfortunately I can't remember how much the quote was.

My main concerns towards a tankless system was as follows:

- These systems are still sufficiently new, so it is difficult to tell how good it's long term reliability / service life expectancy are. My plumber say the non-electronic portion of the system should outlast the duration of my long term stay in the house, but manufacturers would only offer a 1 year warranty on the electronic portion of the system.

- I remember my plumber saying that the system will need 3 inlet/outlets -- don't quote me on this, but I think they are for intake, exhaust, and a smaller additional one for some sort of slight acidic venting type of thing. At my place, this means he will need to drill 3 holes to the outside and build the necessary piping as well.

I did not like the idea of drilling and new additional piping because of the way our place is set up. In particular, a section of the piping will inevitably need to be visible unless I want to start majorly tearing up walls, and that is definitely something I did not want to do. So a replacement water tank it is.

Traum nailed it in the head for me, and for the same reasons we didn't go with the tankless system. I felt that our house, being 35+ years old, wasn't ready for any additional drilling and new holes to be put in, so rather than risk installing the tankless system, and deal with a potential plight of only a year's warranty, the original hot water tank did the job, and for the cost (including a new furnace installed) paid off in itself very quickly. The tankless sytem would have taken a while to amortize, including any cost savings on energy bills.

My plumber was also trying to push a tankless system as he was a registered installer for a brand, I forget the name (Linai maybe?) He quoted me roughly 3K for everything installed. I told him I’d think about it. We only have 2 bathrooms in the entire house including our suite

In the end I ended up using a friends plumbing company account and bought a 80L tank I believe? It was suppose to be good for a household for up to 8 people for under $900, direct cent high efficiency system

I figured it would take some time to recoup the difference and even my plumber was pretty impressed at the $900 tank, he’ll it may have even been like 700 now that I think of it

In our basement there's direct access to a few inches of exterior wall above the foundation so running a new exhaust line isn't an issue, that was done for our furnace too. I'd forgotten about the sealed exhaust system on the tankless which is a plus since there's less risk of CO.

As I've never dealt with a tank failure (knock on wood since the one down there now is 11 years old) is it a slow leak or do they start just dumping water everywhere? That'll be a factor for me too since the furnace is right beside it and all the home theatre stuff is right through the wall beside it.

I think they just explode or at least rupture.

We had no drain for ours so as part of our basement Reno I actually cut a channel in the concrete basement floor and ran a pipe out to tie into the rain water leader. My plumber said that with the tray under the tank will generally pick up the majority of the water if it was to rupture

The "typical" life expectancy for a hot water tank is estimated to be about 7 to 10 years tops, and sometimes that is pushing it. Ours lasted for 14, closing in on 15. The tell tale signs for us is that it was no longer efficient in holding in the heat, and water started to leak. One winter, it just gave up on life and dumped water everywhere. It was a pretty shitty situation to be in, especially if you have kids.

Looks like you're circumstances make you a good candidate for a tankless system. They appear to be popular in new condos and town homes these days, and I have yet to know of any failures. You can be our rat lab! :D

I might toss in a sump pump to be safe regardless of what we get. There's a spot for it in the foundation but nobody ever installed one.

According to my initial research tankless has been around since the 90's, so hopefully that means the 20 year rating is based in actual fact and not just a "we guessed based on the lab testing" kinda deal.

We are going to be installing a tankless unit soon, but the main benefit is never running out of hot water. Efficiency is just a bonus, but don't expect it to pay for itself. The units itself are also supposed to last 20 years+, but there's some maintenance required that you don't have to do on a traditional tank.

One of the drawbacks is that it's not "instant hot water", and you may have to wait for awhile depending on how far it is from the unit. We are going to get one with a re-circulation pump built in, so that every once in a while (either app/timer or via home automation), it will draw and circulate hot water internally, so that when you do want hot water, it should be a lot faster.

Just how much of a delay is added with a tankless? Currently the tank isn't really close to anything other than the washing machine so there's a delay before you get hot water already, if it's just waiting a few seconds more it isn't going to be noticed.

Talking to the guy that came today the system they use will have no problems with our 2.5 bath place. Fortis also has a $1000 rebate for tankless vs $200 for a tank so that brings the price a little closer which is nice.

I've heard up to 30 seconds from tap on to the furthest run in the home from clients who have this system in < 3,000sf 2-3 storey homes. Could be longer depending on the run as the line itself needs to be completely purged of cold water.

The recirc pumps definitely help reduce the time but seems on average hot water delivery is a little slower than traditional tanks. The primary benefit is hot water availability.

The unit has to do a purge cycle before it can fire up, thus the delay.

I have no gas at my place, so tankless wasn't an option (electric tankless has insane power draw; would've had to upgrade the panel). I went with the tanks we use for reverse osmosis water at work which have been extremely reliable, Rheem Marathon. Obviously, efficiency can't touch gas, but it's still pretty good, and lifetime warranty on the tank.

The lines have to purge anyways so that's no different from now, a quick search says around 15s extra for the unit to get hot which isn't a big deal.

While searching for these I found out about point-of-use tankless as well. I assume they're electric only but they're only a few hundred bucks each. In a new build it'd probably be worth it even with the increased power bill since you're cutting out the cost of a central hot water system and the plumbing for the hot lines.

Same for me last year when I replaced my tank - electric tankless would heave required another panel to run, so we went with a Rheem and it has been a great unit. Now in BC, you are required to run the cold line into the bottom of the tank, they say it is for better efficiency; so beware of that during an install, as you may need some extra flex hoses should you go that route.

Bump on this thread.

Looking to see if anyone made the jump for a tankless system since the last post in the thread. I'm in the market for a new place and not sure if it's worth converting to tankless or not.

OK since I've had mine for almost 6 months now, I'll comment:

Ours was a gas condensing unit and required new venting outside to our roof, which required strata approval for our townhouse.

It(Rinnai RUR199in) has all the bells and whistles including a re-circulation pump that I could schedule (on my phone) when I want the pump to work and pre-heat the water, sort to speak.

When I use hot water during the pump schedule, it comes on almost in the same time as regular hot water tank. When it is outside the schedule, it will be slower and noticeably so. It is even slower than units without a re-circulation feature. Sometimes, it does not even come on at all. I think this is due to some of my faucets being "green", so it does not meet the minimum flow rate for turning on the tankless unit.

In times like that, I have to reach into my phone and press the "recirculation" button on the app. Or I turn on a faucet that I know that will turn it on instantly (i.e. my bathroom faucet that's closest to unit). Some people recommend scheduling the hours you will be at home, but we just keep it on in the mornings for when we know we will be taking a shower.

As for efficiency, I can not speak to it as we installed it before moving in. From looking at my hydro bill, it does seem lower than "comparable homes nearby", but unfortunately it does not list the historical records of the previous owner. I'm not sure if the efficiency will ever justify an extra ~$5K of costs amortized over a 15 year period, so I wouldn't do it for only that reason. My unit has a warranty for 15 years and expected life up to 20, I think. My costs also include some repairs and additional plumbing to our stupid tiny air handler that uses hot water to heat the coils, so your installed cost will probably be less.

We are fortunate to negotiate the cost of the tankless into our offer when we found out the normal tank was leaking during the home inspection, so we essentially got this tankless for free.

Now, the main and only benefit is that I NEVER again have to worry about taking extra long showers, or taking a shower immediately after someone else takes a nice long hot shower. Only YOU can figure out if that's worth the price or not.

Well I guess not having to worry about leaking tanks again is another benefit...

that sounds like a pain/headache for paying what amounts to 3-4 times the cost of a regular tank system..

We've been loving ours since we had it installed earlier in the year. With the rebates IIRC it was about double the cost but you get double the life so that cancels out (I didn't get anything nearly as fancy as what Hakkaboy has though). Thus far there has been no downsides, they were able to move it from where the old tank was so now the bathrooms get hot water faster than they did before which was a bonus.

Even ignoring any potential cost savings or increased lifespan I'd do it again in a heartbeat for the endless hot water and not having to worry about having a tank flood my basement.

Normally a hydronic heating system will be a closed loop system treated with molybdenum or glycol, so it's kind of weird to see one running off of untreated domestic water (open loop?). I hesitate to think of how fouled the coil would be after several years of untreated water.

An inconvenience for sure, but can be mitigated a couple of ways:

1. If you have a 9 to 5 job, then you could schedule it turn on in the mornings before work, and then schedule it for 7 to 8pm for when you might be hand washing the dishes or use the bathroom. This is just an example of a schedule, and you can set multiple schedules by day of week

2. You buy a physical wireless button (or 2) from them (or home automation system) and install it somewhere where you want turn on the pump before you use the faucet, which is very similar to me pressing the button on the phone app

3. Similar to a button, you could buy motion sensors for your bathroom(s) and use home automation so that it will activate the pump when someone walks into the bathroom

As mentioned, for my bathroom on the bottom floor closest to the unit, it behaves almost like a regular unit in terms of hot water time, even out of schedule. My bathrooms on the 3rd floor, however aren't that lucky, so I'm used to washing my hands in not so warm water when outside the schedule.

My dishwasher,washing machine, master shower have no problems with hot water, even out of schedule and does not require me pressing the "button".

Could you shed more light or elaborate on this, please? The townhouse I'm moving to has a hydronic system, and based on the home inspection, and a few quotes from HVAC contractors, they all said the hydronic heating system at the place would be good for AT LEAST another 7 - 10 years. The hot water tank is a rental, but I did think of replacing the rental unit with my own Rinnai RU160iN tankless system.

If it's going to fuck up my furnace, I'll stick to a hot water tank. :D

It doesn't really make a difference if it's a tank or tankless.

Is your hydronic system supplied with potable water or is there a water-to-water heat exchanger that transfers heat from the hot water tank to a separate loop for the hydronic heating?

If you're using potable domestic water from your hot water tank or tankless water heater through your coils, that water is going to have a pH around 7 (hopefully not below 7), lots of dissolved oxygen, other chemicals (e.g. chlorine, fluoride, etc.) which can cause damage to parts if they're not designed for it (which hopefully everything is). There's the potential for corrosion, but there's also scale buildup, sediment buildup, and biological growth that will also come with untreated water. This will generally be worst where water stagnates or has low flow (like the inside of your heating coils). When your coil starts to get fouled with these things, it reduces efficiency and performance and can eventually plug it completely.

I will admit that I don't know 100% whether it's using potable water, or if there's a water-to-water HX. I'd really have to triple check on a follow up visit. All I know is there is a hot water tank that appears to feed the hydronic furnace for heating. If it means anything, the furnace is serviced once a year, and has a solid history of service since it was put into service.

I guess if you have a bunch of people living in a house running out of hot water can be a concern, but really, you guys can run out of hot water on a 90-110L tank? Jesus lol..