All Over the Map Hot Water Heater Questions

[statjunk]

Hey guys,

Well I'm in the planning phase of a new hot water heater for an up north cabin. Right now there is a 5 year old electric water heater in there and I'm planning on switching it over to gas for the cost savings. Having visited this board for many years my plan was to purchase a Bradford White but from the posts it seems like that might not be a good idea. I did go to the website and was kind of shocked at the number of seemingly electronic/computer systems on the tank. Seems like a lot of moving parts.

I have a bunch of questions so I'll just write them in list form:

1) Is Bradford White not the go to brand anymore?
2) Is switching from electric to gas really going to save me enough to warrant the switch?
3) Are there any arguments that I should know about for electric vs gas for a vacation home?
4) Since the tank won't be in use very much since it's an up north cabin, what is the shortest amount of time away that will warrant shutting the tank down as opposed to just leaving it running? Is it different for gas and electric?
5) The water tank is in a basement. Does that mean for a gas tank I need a power vented unit?
6) What is the theoretical limit on how long the vent can be? I might need to go as far as 25 feet to vent it.
7) Since the basement floor is cold, should the tank be elevated? If so what is the best method?
8) I have a softener installed that works really well. What should I be aware of with the soft water being in the tank? Does this mean I should drain the tank each time?
9) Will wrapping my tank in insulation improve it's efficiency to be worth going through the trouble?

I really appreciate any time that you guys take to answer the questions above. I want to make sure that I spend our money wisely since it's seems harder and harder to come by.

Thanks

Tom

[Dana]

Operating costs wise we'd need to know what your gas & electric rates are.

"Up north" means different things, and has different implications depending on if you lived in Los Angeles CA vs. Denver, CO vs. Whitehorse Yukon, eh? What is the freeze potential?

Atmospheric drafted gas fired tanks work fine in basements, in 1-3 story homes. There are no vertical length limits (some horizontal limits, an horizontal needs a minimum slope) but the diameter needed is a function of both the burner size and total effective length (including factors for any ells & tees). Vents that are oversized for the BTU-output of the burner leads to condensation in flue and potential backdrafting.

There is no particular efficiency advantage to elevating the tank off the slab unless the tank has no insulation on the bottom, but being elevated keeps lowers the flood-damage risk. In a less-insulated electric tank putting 1" of extruded polystyrene (XPS- be it pink, blue, green, gray, whatever...) under it and giving it a retrofit wrap lowers the standby loss slightly, but most are pretty good these days, and if it's off most of the time it won't be economic.

Water softeners eat the sacrificial anodes, but keeps the heater from liming up from hard water. It's hard to say what your replacement schedule on the anodes needs to be, but draining it isn't called for. (Draining it may be called for in a high freeze-risk situation though.)

[jadnashua]

Your electric tank could crap out tomorrow, or it could last another 10-years or more. Often, the least expensive option is to replace it when it needs it. If there's a utility company rebate to install one, that softens that decision. Without knowing your relative rates, it's hard to say, but a gas WH (and, why would you heat hot water as in your 'hot water heater'? it's a water heater; if it was hot, it wouldn't need to be heated! - maybe call it a cold water heater, but not a hot water heater!), they generally have a quicker recovery, or in your case, time to any hot water verses an electric, so that could be a benefit. With an electric, you might get some hot a little quicker because the top element comes on first whereas the gas heats everything from the bottom, but the difference may not be huge - but, in the case of the electric, it would just be a little volume of hot.

If you go with an atmospheric vent, it needs to go up and out, generally through the building and the roof. If you get a power vented one, then you can go out a sidewall. There are limitations on where you are allowed to put that vent relative to windows, doors, etc., and total length (that length gets eaten up quickly if you put in multiple angles verses a straight run).

Softened water allows it to erode or disolve more things than water with a bunch of minerals already disolved in it so heed the anode rod issue.

[ballvalve]

If its part time, stay with electric and hang all your winter clothes over it. Propane is a bad buy.

[statjunk]

After reading the feed back on my "cold water heater" and discussing with friends I think I'm going to stick with electric. The only issue that I'd like to understand is the issue with anode. How quick could we be talking here? Every two years?

A supply house near me only stocks tanks with zinc anodes. They say they are superior to the magnesium. Is this true or false?

The house is natural gas not propane.

Thanks for the responses guys. Glad to see that you're still on here Jim. I recall you giving great advice out in the past.

Tom

[jadnashua]

How soft is your water and how much do you use? Those would help determine how long one would last. Each metal can be rated or compared to one another as to its reactivity. The goal of a sacrificial anode is to be more reactive than the base metal (iron) of the tank. This is so that it gets attacked first, and ideally, sacrificed in preference to the stuff you want to keep (the tank integrity). Scroll down to the Reactivity series chart on this Wiki page for a relative rating (not numeric, but you can find them if you wish) http://en.wikipedia.org/wiki/Reactivity_series. The further away from the target metal (higher in the chart), the better it will protect. Now, depending on the pH of the water and other things, some of the anodes can react and leave a smell in the water, but again, that's highly dependent on the water chemistry.

[Dana]

You still haven't said what your utility rates are, or your location. In intermittent use cabin where the hot water heater is off most of the time it can take a coupla centuries to pay off the installation costs any new HW heater unless you have VERY high electricity rates.

But if replacement is the way you want to go, a sufficient gas supply is already plumbed into the cabin, the relatively inexpensive lo-tech wall-hung Bosch P1600-H tankless can be a decent option. You can plumb it with de-liming/draining ports to deal with any of those issues, it neither has nor needs anodes. It's minimum modulation is high enough that it might not be the best choice if "up north" means northern Louisiana, where the incoming water temps are warm enough to make it a PITA in summer. It's enough burner to handle one shower even if "up north" means "northern Ontario", but not enough to run two anywhere. It would buy you a few square feet of floor space, and the "-H" flavor of the P1600 had a flow-powered ignition- no standing-pilot to re-light, etc. and you wouldn't even need to run power to it, and it scores about an 0.80 EF on that type of testing, and it'll beat any atmospheric drafted tank on efficiency even if the EF test over-rates tankless units (which it does.) If there's no freeze risk you can just walk away, come back in spring, there's nothing to turn off. But if there IS a freeze risk, drain it before you go- it holds about a quart, so it might take you 6-10 minutes, 15 if you're REALLLLY slow.

[Gary Swart]

While I'm not a fan of tankless, Dana makes some sense, but you would want to make sure the gas supply is sufficient to run a tankless heater. Electric tankless usually require a larger electric service that most homes have, so you would need to check that out as well. I don't have knowledge about electric rate and NG rates everywhere, but unless your area is a real exception, when you have natural gas available, it just doesn't make sense to use electricity for heating water in your cold water heater. (had to say it) Gas is, as far as I know, the least expensive fuel, the heaters can be smaller and thereby less expensive. Gas will heat you cold water much faster than electricity.

[Hackney plumbing]

Have you considered a wood fired boiler? I've thought about making a small wood fired boiler I could use in the city. Throw a grill on top and cook burgers if anyone says anything about the smoke. LOL

[statjunk]

I'll have to wait to get the bills for the electric and gas. Honestly I'm real bad at record keeping. I will supply that info when I have it.

How soft is the water? Not 100% sure but I have the unit set to cycle at 800 gallons and my incoming hardness is 20ppm. The water feels very soft. I'd have to have the water tested to give a more exact hardness level. Anybody have any ideas on that one? I already got the freebee test from home depot.

I'm definitely not going with a tankless system. I've heard to many horror stories about them and really the cost to me just seems like you can never make it up over a traditional tank.

Here is some more background info. The house was recently only electric heat. It even has a really bad form of electric heat that is located in the ceiling between two panels of drywall. The cost to heat was astronomical. I added duct work to the house and put in a forced air natural gas furnace. I have that system running. In short order I'm going to know the approximate cost to run the hot water tank since we don't have anything else up there that uses electricity other than the lights and stove. I'll have to wait till the spring to find out when we go back.

The house is located in Northern Michigan. Last night it was 15 degrees outside.

So it sounds like I need to know more information before I can decide on the type of anode I should use.

Thanks

[ballvalve]

http://www.inspectapedia.com/plumbin...ater_Anode.htm

http://fierychill.com/catalogsearch/result/?q=anode

A few links for anodes

[Dana]

The horror stories on tankless systems are usually for the more expensive bigger-deal whole house systems, not dumb beasts like the P1600 series (the basic design of which is nearly a century old now.) I was running it up the flagpole only as a lower-maintenance,easier to deal with situation than having to drain tanks to avoid freeze-up conditions. I lived with a similar low-tech tankless for well over a decade in a climate with 0F heating design temps (where it hits negative double-digits a few times/decade) and ~35F incoming water during the cool-water winter lows. I retired it fully functioning when I replaced the heating system in favor of an indirect HW setup with more output. But for the 1-shower at a time situation it was plenty of capacity. The P1600H is a ~$600 unit, atmospheric-drafted (you can use cheap B-vent for the stack) and as dumb as a box o' rocks- no electronic controls. That may be 2x the cost of a lowest-cost gas fired tank, but it'll last 2x as long too, and doesn't need periodic anode swaps. In a cabin sometimes it's worth the another $300 just to recover a few extra feet of floor area.

It does take 117KBTU/hr in, so pay attention to the gas plumbing size requirements, but if it's a short run with few ells it's within the range of 3/4" gas lines. In a cabin-sized building you probably wouldn't have to go bigger than 1", worst case. (You can go up to 125' at 117KBTU/hr with 1" pipe.)

I've recommended this very unit to several people for their ski-houses & condos in VT,NH, & ME, and they're all still talking to me (some even invite me up to ski) if that's any measure. :-)

It has some of the usual tankless quirks- delayed ignition making a short slug of cold between the warm water still in the pipe and the new slug of hot, and it doesn't regulate temp super-well when the flow is but a dribble, and may need a pretty good flow to stay lit in the warm water months, but it's nothing too tough to deal with. (If 50 million Europeans can live with a dumb-tankless HW heater, surely you can, but use IS somewhat different from a tank.)

[ballvalve]

50 million Europeans use the hot water of 5 million Americans, so therin lies the difference.

Most of the heaters in Eastern Europe are electric and strapped to the ceiling of the bathroom, thus keeping the place warm.

And the only 10 head showers are in red light districts or Russian mob McCastles.

[Dana]

The 50 million Yurp-eens who use gas-fired 100KBTU+ tankless hot water heaters use a heluva lot more hot water than 5 million 'mericans, don't kid yourself. Most estimates put per-capita hot water use in the Netherlands & Germany at between 50-60% of US & Canadian levels, but they also use a lot less on laundry or other non-bathing uses, and tend to take showers rather than tubbin' it. These are not the same cash-strapped eastern-bloc folks with unheated bathrooms taking GI-showers with a tepid sponge with a 10 liter tank-let overhead. Folks in richer northern European countries with tankless HW heaters of this size are quite familiar with the "teenager taking endless showers" stereotype. (At least they were back in the '80s when I lived there-I doubt that has changed.) Many (most?) Dutch & German homes & apartments have a dedicated 100K+ tankless for the shower & laundry area, and a smaller one in the kitchen rather than trying to deliver all hot water loads from a single central hot water heater, but some get by with just one. Homes that rely on multiple crummy electric tankless or tiny-tank point of use heaters have it the worst, but those exist primarily in areas off the gas grid. (In NL EVERYBODY has been on the gas grid since ~1990. It made TV news when the last farmer's propane tank was hauled off.)

This is not a Michigan McMansion complete with Jacuzzi and a 10-head master shower tended by hot & cold running chambermaids, it's an "up north" cabin. It may not even have a bathtub, but even if it does, a 117KBTU tankless would still fill it in a reasonable amount of time. In the VT ski condo scenario I've seen as many as 6 sweaty skiers take showers serially with one. It works just fine as long as nobody turns on both the washer AND dishwasher simultaneously while somebody is in the shower. (It takes a pretty hefty tank to support that much load.) Compared to a 40 gallon tank a wall-hung water heater frees up enough floor space for 4-5 pair of ski boots. It's not too tough of a mental task to schedule laundry & dishwasher draws to not compete with a shower during the winter months, and during warm-water months it's enough burner to handle the peak loading of the combined draws.

[statjunk]

You guys are awesome.

Little more on the cabin. It's 1455 sqft with two full baths. One has a two person sized standing shower but only one head and the other has a tub. It has a washer and dryer and water on the fridge door. The only roughing it is outside the cabin. LOL.

Dana,

Can you please send me a link to the type of wall mount water heater you're referring to? Like one that shows one for sale.

I'm planning on posting my energy costs just need to get the bills first. I'll have them by the end of the month.

Ballvalve,

I'm checking into the links. Thanks.

Thanks again guys.