Redesign Water Heater System

Users who are viewing this thread

GeneT

New Member
Messages
6
Reaction score
0
Points
0
Location
Southwest Washington
I currently have a +25 year old water heater that lives in the garage which is at the complete opposite end of the house from the bathroom but it is next to the kitchen (laundry and dishwasher), so for the bathroom I have the long run, takes time to get hot water problem.

A part of this whole possible rework is I that I live in a 1955 construction house with galvanized pipes. I have low hot water pressure going to the bathroom that I suspect is the pipes themselves and the overall pressure to the house could be better. The only exception to the galvanized is 10 years back I gutted the bathroom and in put in copper with a dielectric break to hook to the galvanized supply lines.

Since the heater is very old and also as part of this I'd like to more the laundry the kitchen to the garage and I have some plumbing to change and I'm trying to decide on the best strategy for replacing the water heater and improve hot water to the bathroom.

One thought is to leave the water heater where it is and add a lower powered tankless at the bathroom end. I wouldn't really care if the water was hot, tepid would be fine, really anything but cold. A few years back I put in a heat pump and upgraded the breaker box to 200 amps with the wiring going under the house through my large crawl space. Breaker capacity and wiring to run to a tank less would not be a problem.

I looked at recirculation type systems and as I understand them, the approach doesn't have much appeal to me.

Another thought that does have appeal would be to put in a crawl space water heater. Do folks still use these? The heat exchanger / emergency furnace for the heat pump is located in the crawl space so getting a low boy type water heater through shouldn't be a problem but I have to figure out what would be usable and measure to be sure. I can duck walk under the house and have much better than average height clearance. The heater could be centrally located between the kitchen and the bathroom. It would take a little longer for hot water to get to the kitchen but much less time for the bathroom. The hot water line is insulated but in running new lines I think I can do better.

Moving the water heater would also help in creating space to more the laundry from the kitchen to the garage but I could live with the water heater remaining in the garage.

I’d appreciate any thoughts or suggestions.

Gene
 

GeneT

New Member
Messages
6
Reaction score
0
Points
0
Location
Southwest Washington
Extra noise

I'm not found of the thought of extra motor coming on a little bit before I have to get up in the morning. Also as I understand it and I could be completely off base here, but this it how it was explained to me by the guy at the plumbing store (local - not Terry's) who said the recirc. was done by dumping the water back into the cold water line headed back to the water heater. As my kitchen water is downstream of the bathroom it would turn my cold kitchen water tempid. Is this true or due you run a completely seperate recirc. line?

Either way that way I'm heating up additional runs but saving water. Thanks for the suggestion let me know if I'm wrong about the recirc.

I do try to keep an open mind and will look into this more. - Gene
 

Jadnashua

Retired Defense Industry Engineer xxx
Messages
32,771
Reaction score
1,191
Points
113
Location
New England
If you run a dedicated return line, it has no effect on the cold water temperature. If you insulate the pipes, you lose very little energy. The pumps are generally very small, like 1/25th of a hp, so they aren't an energy hog. If you put it on a timer so it works while you are up, you'll have instan hot water. The pump is essentially silent, and normally installed near the WH, so likely a long ways from the bedrooms. I have one installed under my vanity, and can only hear it if I listen for it.

Another idea is to put a small 4-5 gallon wh in the bathroom fed by the hot water line. You'd have hot water from that tank until it arrived from the main tank...much less expensive than a tankless.

200A service may not be large enough for an electric tankless...
 

Dana

In the trades
Messages
7,889
Reaction score
509
Points
113
Location
01609
Putting a recirculation pump on a 50+ year old galvanized line from a tank that's old enough to have voted for GW Bush (but hopefully wasn't registered to vote :) ) seems like a waste of money to me. The pipe is past service life, the heater could croak at any minute.

Bathrooms typically account for 40-50% of the hot water use- if there's space for a heater in the crawl space below the bathroom, that's where it belongs.

Then, put a smaller tank on the kitchen/laundry end. A 2-4 gallon under-sink mount version would be sufficient if feeding it with HW from the big tank, as jadnashua suggests. The dilution-factor of stagnation-cooled plumbing between the tanks is still going to be less than a gallon if you use half-inch pipe. You don't likely need a real gusher the way 3/4" or bigger would provide to run a laundry or sink, but you may want it in the shower. Longer draws would than the mini-tank's capacity would see a slight dip in temp as pipe clears after a long stagnation period, mixing with the locally heated water in the mini-tank- the depth of the dip is minimized by higher volume, but even a couple of gallons should be enough to keep it from dropping much below 100F if the crawlspace always stays above 50F. Insulating the line feeding the mini-tank from the big tank minimizes the dip in temp on subsequent draws. The little Bosch Ariston point-of-use tanks stuff into some pretty tight sink cabinets mounted to a sidewall, but it can also be wall mounted above/behind the laundry in the garage to save space as well. (They plug into a standard 15A wall socket.) The biggest one is 7(?) gallons, but that's overkill- the 2.5 gallon version should do it, (for less than the cost of a decent recirculation system. They're available online for well under $200 if you can't find 'em locally.

GLTIL.gif
 

GeneT

New Member
Messages
6
Reaction score
0
Points
0
Location
Southwest Washington
Thanks a bunch.

Fellows thanks for the discussion and ideas! I will do more research and decide on an approach. There's no question that I want to replace the line, I'd be surprised if it wasn't 1/4" instead of a 1/2" pipe by now but that wouldn't preclude using any of the ideas presented.

I hope the water heaters made today are better than some of the appliances I've been looking at. Most of mine are at +24 years and the constuction of new appliances and their warranties left me unimpressed. I hope the water heaters are as good as the Toto Drake Toilet I bought on the adivce found in these forums!
Gene
 

Inspektor Ludwig

Journeyman/Inspector
Messages
167
Reaction score
0
Points
0
Location
In the good ol' UPC
You could try a small hot water on demand for the lavs. I believe Chronomite makes a small one that plugs in. You have to use the flow restrictor that screws on to the faucet outlet but there's no T+P drain to worry about.
 

Gary Swart

In the Trades
Messages
8,101
Reaction score
84
Points
48
Location
Yakima, WA
I have used a recirculating system for over 6 years. I do not have it on a timer, so I have instant hot water 24/7, but some folks use a simple timer to turn it on/off so it does not run all of the time, but I believe the motor is so small that the cost of operation is a non issue. It uses a return line so the cold water line is not involved in any way. My system is a Laing, but there are others that are likely just as good. You can Google Laing and see what is involved in the installation. Now, this is not going to cure the ancient galvanized pipes, that is another problem you are going to have to face up to.
 

ChuckS

New Member
Messages
93
Reaction score
0
Points
0
Location
Aurora, CO
Putting a recirculation pump on a 50+ year old galvanized line from a tank that's old enough to have voted for GW Bush (but hopefully wasn't registered to vote :) )

You mean ACORN missed a chance to register a WH. They must be slipping.
 

WorthFlorida

Clinical Trail on a Cancer Drug Started 1/31/24. ☹
Messages
5,726
Solutions
1
Reaction score
982
Points
113
Location
Orlando, Florida
It's time to redo it all. Get rid of the galvanize and put in the new plastics. It's easy to run than hard copper and you do lose less heat through the pipe itself. A water heater that old may have been made better than today but back then the insulation on them was not very good. Where you are trying to save money with an fix, you'll save more with a new water heater and even more with a tankless. If you have gas a tankless is easy but if you need an electric one you may have to upgrade the electric in the house.

I once installed a 2.5 gallon under my kitchen sink since it was the about 40 feet of copper buried under slab of the house from the main water heater. This is what I learned.

1) It did provide hot water but after you went through the 2 gallons of water the water went cold from the water in the pipe that was under the slab and after this was flushed out the water then got hot from the main water heater.

2) The temp setting for under the sink heater should be set lower than the main water heater, therefore, when the tanks get filled up with hot water from the main heater, it doesn't stay on and burn a lot of electric. It is good for a short hand wash but for a kichen sink the normal warer use exceeded the capacity of the tank.

3) If you check these small water heaters out you'll notice that there is usually no anode rod to slow up the electrolosis. In less then two years mine started to leak and it did some damage to the cabinet.

4) These little heaters usually have a 1500 watt element and you will need to run a separate circuit from the electric panel.
 
Last edited:

Dana

In the trades
Messages
7,889
Reaction score
509
Points
113
Location
01609
It's time to redo it all. Get rid of the galvanize and put in the new plastics. It's easy to run than hard copper and you do lose less heat through the pipe itself. A water heater that old may have been made better than today but back then the insulation on them was not very good. Where you are trying to save money with an fix, you'll save more with a new water heater and even more with a tankless. If you have gas a tankless is easy but if you need an electric one you may have to upgrade the electric in the house.

I once installed a 2.5 gallon under my kitchen sink since it was the about 40 feet of copper buried under slab of the house from the main water heater. This is what I learned.

1) It did provide hot water but after you went through the 2 gallons of water the water went cold from the water in the pipe that was under the slab and after this was flushed out the water then got hot from the main water heater.

2) The temp setting for under the sink heater should be set lower than the main water heater, therefore, when the tanks get filled up with hot water from the main heater, it doesn't stay on and burn a lot of electric. It is good for a short hand wash but for a kichen sink the normal warer use exceeded the capacity of the tank.

3) If you check these small water heaters out you'll notice that there is usually no anode rod to slow up the electrolosis. In less then two years mine started to leak and it did some damage to the cabinet.

4) These little heaters usually have a 1500 watt element and you will need to run a separate circuit from the electric panel.

Buried in/under a slab is a much worse situation than suspended in a crawlspace- it's like a radiant heating situation: The 40' of copper pipe loses a substantial amount of heat to the ground/concrete along the way, so it's heating up a lot more thermal mass than the just the mix-water in the mini-tank.

The difference in heat lost to the air between PEX and copper isn't very subtantial. PEX has a higher R-value in it's wall thickness, but a much higher surface emissivity (it radiants heat away better then copper.) Whether PEX or copper, it needs to be insulated (R2 minimum if it's semi-conditioned space, R6 minimum if it's a vented crawlspace in a heating dominated climate.)

In this installation wall mounting the mini-tank above/by the laundry in the garage, not under the cabinet makes more sense, since creating more space in the kitchen is one of the stated goals.
 

GeneT

New Member
Messages
6
Reaction score
0
Points
0
Location
Southwest Washington
Interesting Reads

I appreciate all the discussion. I've been tied up for a couple of days with work and computer projects.

The galvanized pipes do need to be replaced. The recirculation line seem more reasonable after reading the comments. I'm still going to consider moving the water heater to the crawl space. There are aspects of that I don't like. I haven't checked code yet but I'm sure I'd need some type of dry well and that would require breaking the vapor barrier. Dealing with a leaking water heater under the house doesn't sound fun.

On the other hand getting it out of the garage would be nice and it's probably a more constant temperature under the house. It could be centrally located and I might not even need recirc. lines. If I needed an auxiliary heater it would be easier to locate under the kitchen sink, or near the kitchen rather than under the bathroom sink for my set up.

I do have gas run to the front of the house. 5 or 6 years back I was starting to look at updating the heating system and was leaning towards gas. The neighbor across the street had gas put in and I got the gas co. to T off and run it to the front of my house at the same time. Ultimately the volatility in gas prices lead me to go with a heat pump. With only the wife and me in the house I'm not sure we'd save much going that direction unless I was to put in multiple appliances. We only need to do laundry on the weekends, not that many loads and the wife isn't a big gas enthusiast so it's unlikely that will happen.

I haven't run the math since putting in the heat pump and probably should do it again for electric vs. gas. Of course with gas there is venting through the roof and a shorter life expectancy for the water heater to consider.

Thanks again, Gene
 
Last edited:
Top
Hey, wait a minute.

This is awkward, but...

It looks like you're using an ad blocker. We get it, but (1) terrylove.com can't live without ads, and (2) ad blockers can cause issues with videos and comments. If you'd like to support the site, please allow ads.

If any particular ad is your REASON for blocking ads, please let us know. We might be able to do something about it. Thanks.
I've Disabled AdBlock    No Thanks