Hot water issue: tankless or recirculation?

Erik Tracy

The wife and I are planning some remodeling in the home.

One thing we want to 'fix' is the hot water supply in the Master shower.

The Master shower is katty-corner upstairs to the downstairs/garage where the gas water heater is - it takes forever for water to get hot upstairs.

I hate wasting all that water - esp in San Diego.

So, I've been looking at two options:
1) tankless water heater
2) recirculation pump

Both have pros and cons.

I've seen ALOT of horror stories with the tankless approach - everything from crummy products to faulty installations and the need to re-pipe for gas, or extra electrical circuits.

The recirculation has options too - some need outlets under the sink, some waste energy by constantly recirculating hot water and hence more gas heating costs.

There is one recirculation option with a bypass valve on a timer or thermostat that seems like a good option and these come with extensions so you can plug them into closeby outlets.

Anyone else have experiences or opinions to share?

disneyjoe7

I think you can have it re-piped so the heat in the pipe helps return cooler water back to tank with the need for a pump. The tankless idea is nice also if installed at bathroom, but you would need to have electric ran also to bathroom.

NJPOLKER

Just move to New Jersey

jimmydep

Take a look at this retro-fit recirculating system by Grundfos.
I've used many of these in existing homes, with great success, you can usually find these for less than $300.00. PM me before you do anything with a tankless system.

http://www.grundfos.com/Web/HomeUs.nsf/Webopslag/PAVA-56TMVA


Jimmy

Rev. Hayes

If you have a good space to put it and are willing to run a gas line then a Rinnai tankless would solve your problem in the most efficient manner. Locating these systems inside a bath can be difficult and I would caution you away from buying through or having "the gas company" perform the installation. In the past I've noted that they show very little regard or creativity with their placement. (at least in my neck of the woods)
If you haven't already I strongly suggest finding a good general contractor to assist in making any remodel decisions. We... errr they need work right now:p

If the tankless turns out to be impractical for whatever reason and you choose to go with the recirculation method I would consider augmenting with a solar water heating system. That way you wouldn't be wasting as much gas and you would be making the most of that hot hot hot roof of your's. esp in San Diego

jimmydep

Rev, with all due respect, gas appliances are not allowed to be installed in bathrooms or bedrooms, except for a few, very strick exceptions. Check out the International Fuel Gas Code Section 303.3...

Jimmy
Plumbing contractor for 30+ years (retired)
Plumbing and Building inspector for the great state of NJ.

Erik Tracy

I know I can't afford to run gas up into my master bath, and I won't have the money to run extra piping either.

Tankless sounds cool, but the only tankless that would work as a quick source of hot water in our master bath would be electric. Sounds expensive to add a circuit under the sink.

Recirculation sounds like the way to go - but I don't like thoses that do constant recirculation as that would waste energy. There are some that are pump activated, but that doesn't sound very quick or convenient as you have to wait for the water to get hot.

Looks like the timer recirculation units may be the ticket as we only use the shower in the mornings or evenings.

jimmydep

Erik, Take a look at this Lang Autocirc, it works with a thermostat and it shuts-off the pump when the water gets hot. The only problem is it needs electric at the sink and is only good for that main line only, if you have several mains you'll need a separate pump for each.
The Lang is a very quiet and dependable re-circ pump. If you have hard water you'll need to remove and clean the impeller assembly every few years (no big deal).

http://lainginc.itt.com/LG-pump-Autocirc.asp


Jimmy

Erik Tracy

jimmydep wrote: »

Erik, Take a look at this Lang Autocirc, it works with a thermostat and it shuts-off the pump when the water gets hot. The only problem is it needs electric at the sink and is only good for that main line only, if you have several mains you'll need a separate pump for each.
The Lang is a very quiet and dependable re-circ pump. If you have hard water you'll need to remove and clean the impeller assembly every few years (no big deal).

http://lainginc.itt.com/LG-pump-Autocirc.asp


Jimmy

Thanks!

I was also looking at the Grundfos - these have a 10ft cord that I could run from under the sink to an adjacent outlet on the wall in a niche where we have our waste basket - would be easy to route and hide.

The Grundfos also has a timer for 15 minute intervals and is reasonably priced.

jimmydep

Both the Grundfos and the Lang are quality products which will give you years of trouble free service. This is the one I use in my house with 3 comfort valves installed at different locations.

http://www.grundfos.com/Web/HomeUs.nsf/Webopslag/PAVA-56TMVA

As a side note, these are very small pumps they use a minimal amount of electricity, but setting the timer so the pump works when you need it is a good idea, just make sure you turn it on about 1/2 hour before you need hot water.

Jimmy

Erik Tracy

Lasareath wrote: »

Jimmy,

How does that thing work without a return line?

From the product description, they tie the hot line into the cold to dump/recirculate the hot line that has cooled off into the cold line.

A downside is that your 'cold' water is not really 'cold' at first turn on...not a big deal for my intended use in the upstairs master bath to get hot water to the shower. I don't really like ice water to wash my face or brush my teeth in the sink anyway....life is about tradeoffs, eh?

jimmydep

Lasareath wrote: »

Jimmy,

How does that thing work without a return line?

Sal it uses the cold water line as the return, so when you turn on the cold you get about 5-10 seconds of tempered water, about 85 degrees, not really a big trade-off considering you get almost instant hot water.

Jimmy

jimmydep

Lasareath wrote: »

Ok, Here's another stupid question:

Isn't the cold water pipe under pressure?, How does the pump fit the hot water into the cold water pipe?

Does it push the cold water back through the water meter?

No....It circulates from the hot line to the cold line and back to the heater. If you go to the wesite it has an animation on how it works.
You need a special fitting that you connect under your sink, it has 4 connections. a hot and cold connection from the water supply, and a hot and cold connection to the faucet. The valve allows for a cross connection between the hot and cold water lines.

maximillian

If I can re-use this thread for a similar problem...

I have a large electric hot water tank (40-50 gal ?) in the basement. I live in the outskirts and only have oil heat. For the most part it works but I fear that is inefficient. I thought that with such a large tank that we should be able to get several showers in before we run out of hot water. However, with guests we get about 3-4 showers before the water appears a little on the cool side.

I was thinking of replacing this thing with a tank-less to be more efficient and to give us much needed storage room in the basement.

Erik, do you think the "horror" stories apply in my situation as long as I get a reputable installer?

Is this a good idea? If so, what brand should I probably go with? Estimated cost?

Thanks.

jimmydep

Max, What type of heat do you have (hot water, hot air)?

2 to 3 normal, consecutive showers will easily deplete a 50 gallon electric water heater, and it would take about an hour before you had enough for the next shower.

What horror stories are you referring to?

Erik Tracy

jimmydep wrote: »

Max, What type of heat do you have (hot water, hot air)?

2 to 3 normal, consecutive showers will easily deplete a 50 gallon electric water heater, and it would take about an hour before you had enough for the next shower.

What horror stories are you referring to?

I think he was referring to me and what I found just by googling tankless water heaters.

Consumer Reports has some on-line info and then from there I surfed around various home improvement forums and found quite a few 'horror stories' about installation mistakes, problems with brands, etc.

That's why, for me, the recirculating pump seems to be easier, cheaper, and since I already replaced my old tank water heater with a more efficient gas model - I really didn't think going tankless was the right choice, for me.

Willow

FWIW, we tried having a tankless installed. We have in the ensuite a single shower and a large roman tub. After filling the tub there is usually not lots of hot water left. So I thought let's get a tankless. Great! instal comp. comes over to be sure of what they will need. (our house is only 3.5 yrs old) They confirm they do not need to run extra lengths of gas line. Perfect, no extra charge. We go outside to look at the vents, bad news. He said since the tankless puts out so much heat the vent/exhaust will need a retro fit due to building codes in our area. No go! they told me it would not be worth while spending the extra on the retrofit as it could go as high as a couple grand. Ok next option, a bigger HE gas HW tank. Again no go they would have to retro-fit due to changes in building codes. Holy crap- a just shy of 4 yr old house cannot even get upgrades without us getting a second mortgage. So he said, just turn up the temp on your current one, which is already close to max. So we are stuck with our current HE gas HW tank.

maximillian

Jimmy,

My tank might be bigger. It's considerably larger than the 40 gal tanks I normally see in someone's home. I don't know why there is such a big tank in this house. Maybe it's 60 gal. The house is 10 year old. Maybe there is too much deposits in the tank.

My heat is forced air with an oil furnace. Whatever I change to would probably be electric still. No natural gas on our street,and I don't want to install a propane tank.

I was referring to Erik's first post in regards to horror stories.

dpowell

We installed a Bosche tankless when we did our remodel. We chose the external mount model so that there was no additional ventilation to do. It works well but we still have to wait about a minute for the hot water to arrive due to the installation location of the unit. It was a very easy installation.

BTW, good to know there's another polkie in the San Diego area. What part of SD are you in?

Erik Tracy

dpowell wrote: »

We installed a Bosche tankless when we did our remodel. We chose the external mount model so that there was no additional ventilation to do. It works well but we still have to wait about a minute for the hot water to arrive due to the installation location of the unit. It was a very easy installation.

BTW, good to know there's another polkie in the San Diego area. What part of SD are you in?

PQ...you?

Everyone's situation and choices are different. Waiting for hotwater means water down the drain. So that's why the recirculating pump seems like a good fit for our house in the Master Bath. With a timer, we can have the pump come on just in the mornings or evenings when we take showers.

dpowell

Escondido.

Makes sense. Hindsight being 20/20 if I had to do it over again, I would have given a bit more thought to plumbing layout to shorten distances to faucets, etc. where possible.

madmax

I have a long run to the bathroom and have to wait for the water to get warm also. I measured it and found that I waste about 1 gal each time. I have been thinking about routing hot water to the toilet. That way when I flush it will use up that cold water before I turn on the shower. Good idea or bad idea?
madmax

dpowell

Assuming you don't flush too much, the warm water won't have a chance to release the arromatic qualities of your toilet. :eek::p