Power vented hot water heaters
I went shopping for a gas hot water heater today and was suprised that the power vented one(GE)at Home Depot had a pilot light.Aren’t these supposed to be high efficiency units?No high eff. furnace that I know of has a pilot light,the gas valve/hot surface igniter/flame proving control circuit eliminates them.
I replaced my old boiler with a 94% furnace this fall and now I’d like to replace my 25 year old water heater too.With the furnace I know that the secondary heat exchanger removes so much heat that the cooler flue gases have to be driven out with a draft inducing fan motor.Isn’t this the case with power vented hot water heaters,that cooler flue gas can be vented with PVC pipe? My old boiler and hot water heater were vented together into a masonry chimney flue.According to some my “orphaned” hot water heater won’t have the same draft in the flue as with the boiler and should now have a smaller liner installed.(Then how did it draft in the summer time when the boiler was off?)I’d be content to change the location of the water heater anyway so I was thinking of moving it near an outside wall and power venting it directly outside.I wasn’t expecting to see a gas pilot light though.Natural gas prices have doubled in the last two years where I live,and I’m trying to keep their thieving hands out off my pocket as much as possible.
At Lowe’s the only one (Maytag)they had was in a box and the salesman didn’t know if it had a pilot or not.Or much else about it.
At HD their’s was on display,price $543,and even though you could see the thermocouple and the label said so,the guy said their high efficiency heaters don’t have pilots.
At the independant lumber yard,price $488(Richmond), the guy on the phone wasn’t sure what I meant by power vented,but he found them in the catalog.
When I called the plumbing supply house,price $606,(A.O.Smith?) the guy knew that his definitely didn’t have a pilot light, but wasn’t sure if some power vented water heaters had pilots or not.
What’s the scoop?
Barry
Replies
On water heaters the power vent is mostly for cases where natural draft can't be used.
Not for efficiency.
The way that water heaters are rated it only (or mostly) on their standby losses and not on the burner eff.
You can got to there websites and check the spec.
Unfortunately in most cases you have to download the specs for each series in PDF.
Here is a list of top rated WH, but it does not if they are direct vent or not.
http://www.eere.energy.gov/consumerinfo/factsheets/eewtrhtr.html
http://www.eere.energy.gov/consumerinfo/energy_savers/virtualhome/508/water_heater.html
http://www.consumerenergycenter.org/homeandwork/homes/inside/appliances/waterheaters.html
Does your boiler have provision for a DHW coil? If it does forget the Hot water heater and go to the boiler for DHW. Just a thought.
I got rid of my indirect (off the boiler) water heater 6 months ago. It was less than 8 years old. It was a genuine pain. The boiler had to run all summer and the heat exchanger was only about 5X7 inches and about 1.5 inches thick. Change the cirulator pump on it once. I was into it almost a grand Canadian. Long story slightly shorter. I took it out and bought a powervented high efficiency from Home Depot for 650 canadian and changed them in a day. My wife just told me yesterday that we never seem to run out of hot water.
Have a good day
Cliffy
make sure you check the venting requirements. The WH has side tappings in 3"pvc, but you often have to bump up to 4 inch depending on vent length.
I only needed 2 inch abs, the vent goes about 2 feet up then 1 foot out.
Happy St Patricks Day
Cliffy
Gee, I'm kind of a wimp, but I've got bigger abs than that!
Good laugh for the greenest day of the year!
Cliffy
I got rid of the boiler,it was from 1967,and the gas bill was killing me.I took the cover off to watch it fire one time,and thought I could probably open up a side business as a small pet crematorium.
RE Power vented hot water heaters.
I have never installed a power vented hot water tank except for the simple reason that a new high effiency furnace was installed and the old chimney removed. I do not beleive there is any savings as I do not beleve there is a extra heat exchanger of any kind. If you are looking to save on gas use I would look to the heat on demand hot water heaters. I have neve seen one installed though I do know that HOme depot would not be the place to buy one.
George
I have 2 power vent water heaters, and think a lot of them for a couple of reasons.
First, I wanted to do away with an old chimney. And second, less chance of CO2 poisoning.
I've never seen one with a pilot light, but am not a plumber either.
Keep in mind that HD and lowes are LOUSY places to get intelligent advice. I'd suggest going with the one from the plumbing supply house. They're much more likely know what they're talking about. And they'll back up their products with service after the sale.
As of approx. two years ago, no more standing pilots on these water heaters. Goverment regulation. Dealers were/are allowed to sell remaining stock, but no new manufactured units have a standing pilot.
AO Smith is higher quality than your States and Richmonds, which are sold thru big boxes and such. Some plumbing supply houses around here still sell the States and Richmonds ( manufactured by the same company, IIRC), but these are considered "contractor" and "economy concerned HO" units. Not top of the line, at all. The higher price of the Smith reflects the use of higher quality components and you can expect more trouble free performance as a result. Example: higher quality gas valves and controls and higher quality burners. Cheap heaters also have tinny burners.
All that being said, I believe the Smith carries the same warranty period as the cheaper heaters. Still, it should easily outlive those cheaper deals. Even more likely so if you have aggressive water which likes to eat thru a tank lining.
I've installed something like 8 of the Smith forced-vent gas heaters and have had no notable problems with 'em to date............but I do know that Smith had some problems early on during the change-over to the newer controls and HS ignition. To the best of my knowledge, they have all that licked now.
No matter which unit you buy, I recommend getting a spare hot surface ignitor right away and having it on hand. Mighty annoying when the WH goes out on Xmas morning and the whole family is headed your way. That happened to the in-laws just two years ago. Weren't they lucky that I had one on the truck? LOL I'd recommend keeping a spare ignitor on hand for any HS appliance.
List here on an AO Smith 40 nat. gas forced-vent unit is $943. Nobody gets list for 'em, of course. $606 isn't a bad price at all, especially if you're buying at retail.
Edit: That $943 is for an HS ignitor unit. If you're talking $606 for the standing pilot, that may be why. Old stock they want to get rid of. Bear in mind that "all that gas" you spend with standing pilot isn't really wasted. It's helping to maintain the water temp in the tank. Controls on a SP are also simpler and more trouble-free over the long haul. Could equal less maintenance and less expensive parts when something eventually replacement. Might be a wash in reality. Hard to say cause everybody's circumstances and usage vary. The colder the home of the heater, the less that SP gas is actually wasted.
Knowledge is power, but only if applied in a timely fashion.
Edited 3/17/2005 1:06 pm ET by GOLDHILLER
Edited 3/17/2005 1:16 pm ET by GOLDHILLER
"...no new manufactured units have a standing pilot."
Do you mean that no water heaters *AT ALL* can have a pilot light?
Or that only the power vent models are not allowed the pilot light?
Perhaps no form of government needs great leaders so much as democracy. [Lord Bryce (British historian)]
Boss, To the best of my knowledge (at least in Illinois) manufacturers are no longer allowed to make and sell WHs with standing pilots. This I am told by the guys at my main supplier. Suppliers are allowed to sell old stock that still has a standing pilot though. I like to think these guys aren't jerking my chain. Oddly enough, I can still order a unit heater with either hot surface ignition or a standing pilot. Go figure. Knowledge is power, but only if applied in a timely fashion.
Thanks to the those responding.I'm not sure which way I'm going to go yet.
I know that Lowe's and HD guys can't tell you anything more than what's on the label of something.No matter how litttle they make you'd think they would try a little harder to master their products.Usually I try to do my own research on the Internet and then know what I want when I walk in the door.Lowe's and HD are so big it's hard not to take advantage of their buying power.(But no I won't stoop to Sam's and WalMart).
Looking at their spec sheets the Richmond(made by Rheem) has the best first hour and energy factor rating.All the sites though have the "We might be bull$hitting the government and ours is just like everybody else's" disclaimer.Their price is more than a hundred bucks lower than the supply house.
The A.O.Smith at the supply house I'm sure is better built,but on their website,they have a gazillion models and I'm not sure which the counter guy was quoting.They have some that vent with 2" or 3".They have some that are sealed combustion so that you have to take TWO 3" out.I could do that mechanically but I'm not sure that I'm that obsessed with not using conditioned air for combustion.Then they have direct vent models that you use larger diameter metal pipe to vent a short distance but with no fan motor.
I guess part of my misunderstanding about these units comes from them using PVC for venting.I figured the flue gas must be much cooler than the older ones.There's no way I'd use PVC to vent my current 80's model,that gas is HOT.
Hey,Goldhiller,is that a Basset or Beagle pup on your profile?I have a 5 month old beagle that's a lovable,troublesome little $hithead.
Barry
That there is a beagle and not a pup at the time of the photo.Actually, that fella belongs to my brother. Buster's the name. Quite the dog, too. Very lovable, but don't let him off the leash outside. He be gone. Wherever and whatever his nose finds interesting.....has his immediate attention and off he goooooooooooes. Even with those little short legs, he can run much faster than you can. <G>Knowledge is power, but only if applied in a timely fashion.
Power vent or not, traditional water gas heaters have miserable efficiency. Despite confusing rating systems, realistically you are looking at 70-75% net thermal efficiency in most cases.
If you want efficient, look into the Polaris or similar units. They have sealed combustion, and amazing thermal efficiency. Stack temps are so low they use PVC, just like your furnace. 95% +. Of course, the downside is the price.
http://www.americanwaterheater.com/WHBrowser/commgas/polaris50.cfm
Yeah, it's really difficult to lay down two grand for a hot water heater (polaris), but it's a sweet looking unit.
Just wanted to remind you of the noise factor. I spec'd a unit and when I asked about noise the salesman said it sounded like a soft blow dryer. More like a soft tuba. Fortunately the owner doesn't mind. It is side vented for shorter run and better efficiency, but eventually will vent up to roof to hopefully reduce the sound.
On demand, controversial in this forum, but an option too?