Water heater replacement questions
June 4, 2011 11:30 AM Subscribe
Water heater replacement questions...
Water heater decided my basement needed a river in it. . Currently have a 40 gallon gas heater. Any reason to go with a bigger tank (50 gallon) or a tankless model? Prior to the flooding our only complaint was that it sometimes would take 30 seconds for hot water to start flowing.
Thanks!
Water heater decided my basement needed a river in it. . Currently have a 40 gallon gas heater. Any reason to go with a bigger tank (50 gallon) or a tankless model? Prior to the flooding our only complaint was that it sometimes would take 30 seconds for hot water to start flowing.
Thanks!
Best answer: Bear in mind that you can't just increase the size of the tank--you'll almost certainly have to rejigger the entire piping set-up to accommodate it. This will cost $$$, and will require a heating contractor, as opposed to the usual big-box store installers.
I've got one of the higher-end tankless models, a Navien combination boiler (supplies both the baseboard heating & hot water). Positives: very high-efficiency; endless hot water! Negatives: it also takes about 20-30 seconds for the hot water to get going, which is pretty standard for a tankless heater; hard on the wallet (about $8K including labor, although there were tax incentives to ease some of the pain).
posted by thomas j wise at 12:07 PM on June 4, 2011
I've got one of the higher-end tankless models, a Navien combination boiler (supplies both the baseboard heating & hot water). Positives: very high-efficiency; endless hot water! Negatives: it also takes about 20-30 seconds for the hot water to get going, which is pretty standard for a tankless heater; hard on the wallet (about $8K including labor, although there were tax incentives to ease some of the pain).
posted by thomas j wise at 12:07 PM on June 4, 2011
Best answer: We have tankless (on demand) heaters in three properties. There is a delay before the hot water starts, but it keeps on pumping once it does. One unit also runs radiant heat for a 800 sq ft studio. The studio unit will not have a delay if the heat is on, but in the summer it does. I love them for their efficiency, but the delay can be annoying when all you want to do is wash your face or hands. A friend I know has one with a storage tank that lessens the delay quite a bit, but then you have both a heater and a tank. The big one ( and my friend's) are NTI, and cost north of 10 k installed with the radiant. The other two are hot water only Rinnais which cost about 3K installed.
posted by lobstah at 12:11 PM on June 4, 2011
posted by lobstah at 12:11 PM on June 4, 2011
Best answer: Sure you can increase the size of the tank. Replacing one tank with another almost always requires rejiggering the lines. Changing to a larger sized tank won't require any more or less changes to the pipes than a same-sized tank would.
But a larger tank would do nothing to affect the time-to-hot situation. The larger tank would just let you run the shower longer or fill more of the tub with hot water. Depending on how old your previous one was a new one is VERY likely to be a lot more efficient. So going with a larger tank might still end up consuming less energy than your old heater.
Also bear in mind it takes longer to reheat a larger tank. So when you use all the hot water it'll take a bit longer to bring the new cold water back up to temp.
Tankless gives you essentially limitless hot water. While saving energy by not keeping a huge tank of water hot all the time. The trade-off is the units are generally a lot more expensive and installing one may require more changes to the plumbing and exhaust than would a tank of the same kind.
The better question is why is your tap so slow to get to full heat? Low water pressure? Or poorly insulated hot water lines? It might be worth considering wrapping the hot water lines with insulation (designed for the purpose, of course). That might help keep the water in the line a bit warmer and thus shorten the wait.
posted by wkearney99 at 1:44 PM on June 4, 2011
But a larger tank would do nothing to affect the time-to-hot situation. The larger tank would just let you run the shower longer or fill more of the tub with hot water. Depending on how old your previous one was a new one is VERY likely to be a lot more efficient. So going with a larger tank might still end up consuming less energy than your old heater.
Also bear in mind it takes longer to reheat a larger tank. So when you use all the hot water it'll take a bit longer to bring the new cold water back up to temp.
Tankless gives you essentially limitless hot water. While saving energy by not keeping a huge tank of water hot all the time. The trade-off is the units are generally a lot more expensive and installing one may require more changes to the plumbing and exhaust than would a tank of the same kind.
The better question is why is your tap so slow to get to full heat? Low water pressure? Or poorly insulated hot water lines? It might be worth considering wrapping the hot water lines with insulation (designed for the purpose, of course). That might help keep the water in the line a bit warmer and thus shorten the wait.
posted by wkearney99 at 1:44 PM on June 4, 2011
Echo what others said about the wait for hot water, if you want to decrease the wait time, install a hot-water recirculation system. At my cousin town house, they have a button installed near the sink. Pressed it once before entering the shower = instant hot water.
Regarding exchanging for a larger boiler; it'd be more inefficient keeping a larger volume of water heated, so, you should only choose one that sized for the number of people in the house. Larger boiler will need to pull more energy (=upgrades to the gas/electric system) and will need larger pipes (to bring those hot water to places needed it). I don't think it's required to have larger pipes, but I think the gas/electric upgrade is required. Check your building code and with your city hall regarding permit required for this. Water heater is a major focus for safety in the house, where you have water (= water damage + draining requirement), energy (= fire hazard), ventilation (if it needs combustion) and structural (= bracing for earthquake, tank explosion, or ran-into by a car) requirements, all converge at the same place. Generally, swapping out is fine, but if you want to get a larger one, or relocate it; the permits required can be numerous.
PS: same for the tankless boiler; from what I've heard, it's wonderful (less corrosion, limitless capacity); but it may require upgrade to your gas/electric feed.
posted by curiousZ at 1:44 PM on June 4, 2011
Regarding exchanging for a larger boiler; it'd be more inefficient keeping a larger volume of water heated, so, you should only choose one that sized for the number of people in the house. Larger boiler will need to pull more energy (=upgrades to the gas/electric system) and will need larger pipes (to bring those hot water to places needed it). I don't think it's required to have larger pipes, but I think the gas/electric upgrade is required. Check your building code and with your city hall regarding permit required for this. Water heater is a major focus for safety in the house, where you have water (= water damage + draining requirement), energy (= fire hazard), ventilation (if it needs combustion) and structural (= bracing for earthquake, tank explosion, or ran-into by a car) requirements, all converge at the same place. Generally, swapping out is fine, but if you want to get a larger one, or relocate it; the permits required can be numerous.
PS: same for the tankless boiler; from what I've heard, it's wonderful (less corrosion, limitless capacity); but it may require upgrade to your gas/electric feed.
posted by curiousZ at 1:44 PM on June 4, 2011
If you have the room, i.e. the extra space around the current heater, you should be able to get a bigger heater. A bigger heater will allow for longer showers. It will not make devices far away from it get hot faster. A bigger heater may or may not be available with the same connection height.
A tankless heater at that particular fixture that takes a while would help. However, tankless means new circuits, which you may not have the room for.
posted by notsnot at 1:46 PM on June 4, 2011
A tankless heater at that particular fixture that takes a while would help. However, tankless means new circuits, which you may not have the room for.
posted by notsnot at 1:46 PM on June 4, 2011
You probably don't need a bigger tank. How big is your household? Do you ever run out of hot water, say in the morning with everyone showering? or while taking a shower after doing laundry or dishes? If you don't run out of hot water, there is no advantage to getting a larger tank. It'll just cost you more to keep all that hot water sitting around.
If you have access to the pipes that run from the water heater to the faucets you use most, wrap them with some foam pipe insulation. This is cheap and easy, and will keep the water that's sitting in the pipe at least somewhat warm.
A more expensive solution would be to install a circulating pump to keep hot water always instantly available at the faucet. Here's a surprisingly useful article on this at Wikipedia.
posted by Corvid at 2:04 PM on June 4, 2011
If you have access to the pipes that run from the water heater to the faucets you use most, wrap them with some foam pipe insulation. This is cheap and easy, and will keep the water that's sitting in the pipe at least somewhat warm.
A more expensive solution would be to install a circulating pump to keep hot water always instantly available at the faucet. Here's a surprisingly useful article on this at Wikipedia.
posted by Corvid at 2:04 PM on June 4, 2011
This thread is closed to new comments.
posted by Thorzdad at 12:06 PM on June 4, 2011