I bought and installed a new water heater. High end, high efficiency, PVC outlet. I bought it because I wanted the old one out of my workshop, which included the now unused chimney.
The wife complained that now when she turns on the cold water, there is a slug of hot water coming out. I checked, and indeed there is backflow from the unit.
NOW FOR THE GRUMP: My old, low end, Montgomery Ward heater had check valves on the inlet and outlet. This new one (An “Energy Efficient” unit) does not, but I am invited to BUY this as an accessory. For this I paid $WayTooMuch!
Replies
Maybe the previous installer knew more about what was required than your current installer. Can blame the equipment if the installer is clueless!
I know both installers VERY personally. Each unit was installed only with the equipment supplied by the vendor.
A gas HWH often requires a B flue, but I have never seen it included with the appliance. Same with the valves - I would be surprised to see an accessory included unless it was advertised as a complete kit.
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<I would be surprised to see an accessory included unless it was advertised as a complete kit>
Yeah, I suppose you're right. My grump was that I would think something intended for maximum energy efficiency, and DEFINITELY not a price-point item, would go the extra step.
Also, as a secondary grump, the existance of these things is barely mentioned in the instructions.
BTW, I am glad you are able to take some time from managing the Piffin Screw Company to answer this question. ;>)
Many products these days are being cheaped-out or, as the manufacturers say, "decontented". This allows them to wholesale or retail products at the same price even though their manufacturing costs are increasing. The check valves were probably deleted to make up for cost increases in other parts of the heater. It's a hidden, insideous form of price inflation.
The valves are often required by code. But I don't know that it's typical for them to be supplied with the water heater.
You Know I've heard that the standard gas water heaters were going to shoot up in price because the manufacturers have to change the burner out to a different kind that meets some sort of emission criteria. All the tankless manf reps were talking about it. Its supposed to bring the prices closer together. Could this be why your tanked heater was so expensive?
Daniel Neumansky
Restoring our second Victorian home this time in Alamdea CA. Check out the blog http://www.chezneumansky.blogspot.com/
Oakland CA
Crazy Homeowner-Victorian Restorer
Actually, the water heater was expensive because it has a powered blower and heat exchanger, like the high efficiency furnaces. Although the efficiency is nice (and I think it can be used for the energy tax rebate), the main reason I bought it was because I needed to move it to a location away from the chimney and through-the-wall venting was necessary. And, I was NOT going to use a high-temp vent that gives that ugly heat blackening above the outlet.
That said--it WAS a high end device. And high-end devices usually have the bells and whistles on them even if the low-end, price-competitive devices have a lot removed.
Also, I went to my supplier and complained (about the manufacturer; the supplier was absolutely not at fault and I told them that). They took a set of heat traps and gave me them; I told them that if they were going to eat the cost, it was not right and I should pay for them. They said that they WOULD work things out with the manufacturer.
What does the installation instructions say about installing heat traps..
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A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.
The instructions, on the page identifying the various parts, says in effect "Heat traps may be purchased and installed on the inlet and outlet." This in very unobvious print.
And, to repeat another part of my grump, it currently backflows when the cold water is turned on, allowing my cold water to be tempered. And yes, it is installed correctly. You essentially have a direct connection between the hot and cold pipes (via the tank), without a flow control device.
Edited 8/1/2007 10:26 am by JohnD1
>>Actually, the water heater was expensive because it has a powered blower and heat exchanger, like the high efficiency furnaces.
Just because it has a blower on the flue doesn't mean it is "high efficiency."
The blower mixes a lot of air in with the flue gases, diluting the CO2 and CO, which allows them to be vented through a side wall.
In theory, it might help efficiency a little by also regulating the flow of air into the combustion chamber and through the flame, allowing greater design control of the burner and higher efficiency, but I don't know if the engineers have actually used this benefit in burner design.
So far as I know, there are no "high efficiency" residential water heaters which use a secondary, condensing heat exchanger to reach high levels of efficiency.
If anyone knows of some, I'd like to know.
May your whole life become a response to the truth that you've always been loved, you are loved and you always will be loved" Rob Bell, Nooma, "Bullhorn"
"We Live" http://www.youtube.com/watch?v=7kuBgh0VCqI&mode=related&search
And Annie Ross's "Twisted" http://www.youtube.com/watch?v=8lqivrCIRGo&mode=related&search=
<So far as I know, there are no "high efficiency" residential water heaters which use a secondary, condensing heat exchanger to reach high levels of efficiency.
If anyone knows of some, I'd like to know.>
Not mine, but here is an example of 94%: http://www.htproducts.com/literature/lp-41a.pdf
>>You Know I've heard that the standard gas water heaters were going to shoot up in price because the manufacturers have to change the burner out to a different kind that meets some sort of emission criteria.
A few years ago a requirement was added for equipment to prtevet flame rollout should VOCs get sucked into the combustion chamber from the surrounding air (gasoline fumes for example)
Is that what you're thinking of? Or something newer?
May your whole life become a response to the truth that you've always been loved, you are loved and you always will be loved" Rob Bell, Nooma, "Bullhorn"
"We Live" http://www.youtube.com/watch?v=7kuBgh0VCqI&mode=related&search
And Annie Ross's "Twisted" http://www.youtube.com/watch?v=8lqivrCIRGo&mode=related&search=
No this is a recent devlopment that I heard about at the PCBC a couple of months ago. The tankless guys were saying that it was going to cause the price of even the most basic hot water heater to rise a couple hundred bucks. I poked around online about it but was not able to find anything.
Daniel Neumansky
Restoring our second Victorian home this time in Alamdea CA. Check out the blog http://www.chezneumansky.blogspot.com/
Oakland CA
Crazy Homeowner-Victorian Restorer
Does the hot water slug end quickly? Could it be that the hot and cold water supply pipes are close together and the heat is being radiated to the cold and the wall cavity air is hot enough to facilitate this?
Good question.
The answer in this case is no. The pipes are running along the joists, exposed in the basement. They are about 6 inches apart.
When the wife turns on the cold water, I can feel the hot water coming up the inlet. And, it keeps coming up as long as the water is running.
Edited 8/1/2007 11:00 am by JohnD1
What comes out of the hot faucet? That's pretty weird. Now, you're making me want to check mine out.
"I cut this piece four times and it's still too short."
Interesting! The pressure on the hot side is higher than the pressure on the cold side? Maybe REALLY thin walls in the WH? DO you have an expansion tank that accidently got moved to the hot side of the piping?
Brooks
Unless you buy a back-flow preventer, I'd think there would always be a small amount of back-flow. The pressurized WH will contract slightly as its inlet pressure drops due to the use of cold water.
A) I would expect this to be a bad problem if the WH walls are thinner; it will be acting more like an expansion tank! Solve this with a back-flow preventer.
B) There will always be a SMALL amount of water flowing back. Perhaps the distance between the "T" in the supply line and the WH inlet could be longer? The shorter this length the more hot water can back up through the "T"...
I'm thinking thinner walls on the WH...
Brooks
If you installed the water heater you fuxked up, if someone else did the install, they fuxxed up. Check valves are there for a reason. Without knowing your system I think you or someone else deleted the check valves and screwed the system up, sorry
I'm not saying I have a HUGE amount of experience in this area, but I've never seen a WH with check valves...
As I understand it, they are now required by most codes.But you wouldn't notice them unless you knew what you were looking for -- they look just like regular nipples, more or less.
So convenient a thing it is to be a reasonable Creature, since it enables one to find or make a Reason for everything one has a mind to do. --Benjamin Franklin
You learn something new every day!I put in a new WH in my home last year. No check valves, of course! Are we supposed to put in one on the inlet side, or one on both sides?While I'm fixing it I think I'll consider replacing the cardboard tube I used for vent pipe...
Yeah, there's supposed to be one on each side. They're really heat traps, not true check valves -- probably pretty "leaky" if tested for backflow, but they prevent convection when the water isn't running.
So convenient a thing it is to be a reasonable Creature, since it enables one to find or make a Reason for everything one has a mind to do. --Benjamin Franklin
Recall that my supplier gave me the new heat traps. These consist of a rubber flapper that is simply suspended over the bore, minimizing convection currents.
The old style had a small ball in it, and there was an inlet and an outlet unit. The inlet ball was lighter than water, and (assuming that the water heater opening was at the top, which is every water heater I ever saw), it prevented convection currents AND served as a modest check valve.
The outlet had a ball that was heavier than water, preventing (hot) water in the pipes from going back into the heater.
There have been some complaints over the years that the ball-type of unit causes rumbling/rattling in the plumbing system. I never had that problem.
As I have this nuisance backflow problem, I will try the new units. If I get backflow, I will replace them with the old units.
The only thing that I'm trying to tell you is if they were in the system and you removed them thats a good chance that caused your prob. Since you haven't posted the original hook-up of your system thats the best I can do. FYI there are many domestic systems that have check valves. Sorry.
Heat trap made with some copper pipe and a few elbows will cure the problem. Just be sure to drop the trap by 12" and you'll be cured.
No need for any flappy things.