Tankless Water Heater Advice and or Experience

[Tractor Seabee]

My house has a hot water recirculation Gronfos pump. These pumps wont work on tankless systems. A plumber i know said theres a way to add a small elect water heater inline with a gas wholehouse system, but way too complicated for me. My system is about 10 years old now, absolutely no issues. I drain both water heaters 2 times a year to get rid of any possible buildup. I have a system to use tank water to clean the electronic air filter system, thus cleaning both systems at same time. The water coming from heaters is usually very clean, so i dont think im getting any buildup. I hope to get at least another 10 years on this without any issues....hopefully more. Since its a direct vent system, its very efficient. My master bath is 40 feet from water heater. Without the circ system i would have to waste lots of water to get hot water. With the circ pumpi get near instantaneous hot water.

You can use a circ pump but you have to add surge tank to stop short cycling of the burner. It needs a heat sump (flywheel) to even out the cycles. Just more pieces to the system. I have seen tank-less used as a heat source for small hydronic heating systems, again using a surge tank.

They are a condensing type burner so you have the high acid waste stream to pipe outside not in the sewer or septic system.

Ron

 

[jwstewar]

We moved into our house in 2008. We had the builder install a "Whole House" Noritz tankless. One of the best things we did. Love it. Never run out of hot water, doesn't matter if the if the dishwasher is running, the washing machine, and 3 showers. It is just endless hot water. One thing we did wrong, we put it in the basement on the opposite side of the house from all of the fixtures, unfortunately that has caused a bit of a wait time for showers. We had our first issue with it last fall. The ignitor failed. I ordered a new one online. $10 and free shipping. Took me about 10 minutes to install and we were back in business.

When we moved into the house I did a calculation from the previous house that had burned. It was easy to do the calculation because I used summer months because our usage would have been the same and taken the size of the house and efficiency out of the equation. I figured up we were saving around 100 gallons per year. I figure our tankless has more than paid for itself even with a little bit of extra water usage.

We recently added a small electric (9000 btu) in our milkroom in the barn. It does great for washing the milk machine and clean-up. Now if I hook a hose to it, it doesn't get the water hot, but it is plenty warm enough to give a goat a bath without freezing them to death. We are having one issue with it, sometimes the flow sensor will stick and it won't shut off. Turn the water back on and off real quick and it shuts off then. But if you don't catch it, it will cause the thermal sensor in the unit to trip. I need to flush it with White Vinegar to see if it helps it.

 

[Gary Fowler]

I looked at tankless heaters when we built our new house and after considering the flushing and yearly cleaning required to keep the warranty, I decided against it. Also we dont have natural gas, propane is out of the question due to the cost so it would have been electrical and the current draw is enormous.
I went with a high efficiency 220V 50 gallon tank model with a circulating pump. We have near instant hot water at all the connections (only need to flow from underground connections to shower head) and so far not one problem. We have 3 bathrooms and with all in use, no one runs out of hot water. We put the water piping under the slab with closed cell foam insulation on all the lines so very little wasted heat since the sand is a natural insulator also.

 

[plowhog]

I recently finished building our new residence, a little under 6,000 sq ft. Mostly single level. There were (originally) long runs of plumbing to carry hot water long distances from water heater to faucet, etc. The original design had one tankless heater (propane) in the garage and another tankless in the master suite. One for kitchen, etc., the other for bedrooms. Our master bath has a 77 gallon tub, which of course requires lots of hot water.

Our plumbing contractor is highly experienced with tankless. He reviewed our design and strongly suggested three changes: 1) move the tankless from the master to the garage so the two tankless units are installed together, side-by-side, 2) daisy chain them together, working as a master/slave unit, and: 3) create/add a recirculation loop through the entire house. I initially resisted all of these changes, as I felt the recirc loop defeated the reason to have on-demand heaters. I wanted the savings from not burning any propane unless there was a hot water demand.

After much research, and trust in my plumber's amount of experience, I agreed. This is how our house is built. I am very pleased with the setup. The on-demand tankless units we chose are designed with having a recirc loop, as well as a second unit in series. (Can also work without either.) I now have endless hot water-- no matter how much demand there is. The recirc loop is plumbed through the entire house and goes near every faucet or place where hot water is needed. This is so there is never a long run to get to hot water. You open any hot water faucet, and quickly have hot water. All plumbing under the house is insulated.

Keeping the water in the recirc line hot is a 24/7 requirement. Just like keeping the water hot in a 40 or 50 gal tanked heater. Except its a lot smaller volume to keep hot in the recirc loop, meaning less propane burn to do so. My operating mode is to leave one of the on-demands turned off if it is just my wife and I in the house, and fire up the second one if we have company or guests. I also turn off both of them if we leave for a trip. When we return, I turn one on and we quickly have hot water at all the faucets.

This was certainly a different design and result than I expected, but I have been very pleased with this setup so far.

 

[MF RED in MT]

We have an electric 50 gallon water tank on a well system.

The only problem was the long wait for hot water in the far away master bedroom bathroom.

About 11 years ago, I added a "Watts" recirculating pump to the top of the water heater and can regulate the time and length it's operating.

It has been a good investment of about $100 to have hot water at the first turn of the faucet.

KC

 

[the old grind]

Plumbers used to add a convection loop using a tank's drain cock for return from faucets. This doesn't send water as hot to each fixture, but the goal was to warm pipes somewhat. It's less common nowadays than still using HWHs as heating boilers in cottages and additions, and may have gone by the wayside since Y2K.

Circulating loops are not energy savers, but I contend that any HW source only supplants the heating system during heating season vs wast as much heat as is commonly a__umed. My own plan is to set the HW temp to 'bearable' at both ends of it's heating cycle. MY shower head is slower. I don't wash clothes in hot water. The myth that dishwater must be 'so hot' to kill germs goes out the window when we're told that 20 sec in detergent will do the same.

All that said, life is kinda short to have to wait a whole minute for hot water to come out of a faucet a few times/day. It adds up over the years & all.

 

[Doofy]

During the winter, we wash our laundry in hot water just to help out the septic tank. Cold ground and sub-zero temps most of the winter is hard on septic systems.

 

[YLee Kioti]

Pretty timely post. We just had our slab poured. Have not given our builder any changes since we locked the plans down, which included a tankless NG heater.

But few weeks ago had started rethinking it. Wife says I do over think things, but dang it, tired of making poor/bad decisions. Since we went from carport to garage am considering to ask our builder to install WH (40gal.) in garage instead. Still using NG. The house we sold last year had one and just two of us never an issue.

Thinking simple is good. We do have have hard water and the idea of annual flushing of a demand heater , well the older I gets the less prone to doing maintenance. So less is better. Will be speaking with our utility folks about where to send off water for testing.

Well, yes am pretty cynical so giving the "Hey Culligan Man" a sample for testing means to me an up sell because of their test results.....
Anyways, hope yah'll keep chiming in. Hope our builder don't hate on us fro changing my mind...but...heh....heh...am leaning towards a NG WH.

 

[dstig1]

Thanks for your responses, keep them coming.

Should have mentioned it is for two old people in a small house.

Sounds like we would also have to get a water softener.

These are available and under consideration:

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Your second photo is the exact same model I have, only mine says Takagi instead of AO Smith, as Takagi makes them and AO SMITH rebrands them in the US and handles service and parts for both. Both are sold in the US. Try Supplyhouse.com for good prices and excellent service. And Fast shipping.

 

[Xfaxman]

Thanks :thumbsup: