# Expansion Tank Hot Shot



## Phat Cat (Apr 1, 2009)

Just saw this in a supplier newsletter and it promises a lot. In the diagram with the article, it also says this Thermal Expansion Tank will eliminate the 'cold sandwich' effect on tankless gas water heaters. I tried Googling and could not find anything on Act D'Mand, other than the gohotwater.com which appears to be a link farm. I did find Metlund has a Hotshot Dual Port that has a lot of the same features. Has anyone come across the ones by Act D'mand? 

One thing I thought odd was the article stated "The typical life of an existing expansion tank is around one year on most residential homes." 

Is this true? It certainly has not been our experience with expansion tanks.

ACT D’MAND® Systems, manufacturer of the D’MAND CIRC®
Electronic Control Pumping Systems and Structured Plumbing® Systems
are introducing into the market a patented revolutionary new concept
in expansion tanks for residential and small commercial buildings.
The product is called the HOTSHOT® DUAL™ PORT™!
Expansion tanks have been around for many years; however they are
designed as only an expansion tank to relieve the pressure that builds up
within the hot/cold water lines in the building. Within a few months,
these existing expansion tanks tend to develop buildup in the tank and
inlet thus leading to failure. Plus the water in the expansion tank becomes stagnate as very little of the water in the reservoir is displaced back into the hot water line which is considered potable water supply. The typical life of an existing expansion tank is around one year on most residential homes. Once the expansion tank becomes clogged it no longer functions as an expansion tank and puts added pressure on the water relief valve. The Dual Port comes in two sizes, model 12-A501 2 gal & 12-A502 4.5 gal. WWW.GOHOTWATER.COM


----------



## ROCKSTARPLUMBER (Dec 14, 2008)

Meh, those have been out for a while. Anything else you wanna share though?:laughing:


----------



## Phat Cat (Apr 1, 2009)

Act D'mand? Why can't I find them? This was part of a press release - self-cleaning expansion tank.

Also, do you find expansion tanks failing in one year? We don't.


----------



## Master Mark (Aug 14, 2009)

*in a few years....*



PlumbCrazy said:


> Act D'mand? Why can't I find them? This was part of a press release - self-cleaning expansion tank.
> 
> Also, do you find expansion tanks failing in one year? We don't.


 
I only install them if absolutely needed due to high water
pressure... They seem to get water logged around here
in a few years,,,

we have seen a few of them rust out on the side and actually cause water damage to the home...
the heater was fine but the exp tank flooded out the place

no one checks them after a few years and they dont want pay us to come back out to pump them backup with air either...

we take out leaking heaters and the therm tanks are usually always shot....
 dont know when they finally gave out..

that would be an interesting study to do....

call me about it when you complie some data.....


----------



## Tankless (Jun 12, 2008)

It's basically a standby tank, with duel ports. Made by Larry at D-mand. It is in effect an expansion tank, but is designed really to mix warm / cold / hot water on the OUTPUT side of a tankless heater. There is a bladder in it. They are really new. I got the news a few months ago, but they have not showed up on the shelf yet. And the web site is GOTHOTWATER DOT COM


----------



## PLUMBER_BILL (Oct 23, 2009)

Master Mark said:


> I only install them if absolutely needed due to high water





Master Mark said:


> pressure... They seem to get water logged around here
> in a few years,,,we have seen a few of them rust out on the side and actually cause water damage to the home...the heater was fine but the exp tank flooded out the place
> no one checks them after a few years and they dont want pay us to come back out to pump them backup with air either...we take out leaking heaters and the therm tanks are usually always shot....dont know when they finally gave out..
> 
> that would be an interesting study to do....call me about it when you complie some data.....




On service to a customers home with a therm tank. Usually I have to shut water off. After the main valve is off the next logical step would be to go to a faucet and open it for drain-down. Now if the water runs with some force for 20-30 seconds. The therm tank is working. [It is pushing its pressurized water back into the system] On the other hand when you go to drain down and the water just starts to trickle after a couple of second spurt probably the therm tank is water logged and should be replaced. At least it alerts the experienced plumber that there might be a problem. Now some might say that this is goofy that you should make a pressure test anyway. I had by doing that, a pissed off lady she acused me of taking the air out of her tank just to sell a new. Now I like to tell them the tank is bad without even touching it. 

Comments ???


----------



## Phat Cat (Apr 1, 2009)

Tankless said:


> It's basically a standby tank, with duel ports. Made by Larry at D-mand. It is in effect an expansion tank, but is designed really to mix warm / cold / hot water on the OUTPUT side of a tankless heater. There is a bladder in it. They are really new. I got the news a few months ago, but they have not showed up on the shelf yet. And the web site is GOTHOTWATER DOT COM


Thank you Tankless for backing me up. So there Rock! :smartass:


----------



## smellslike$tome (Jun 16, 2008)

PlumbCrazy said:


> Just saw this in a supplier newsletter and it promises a lot. In the diagram with the article, it also says this Thermal Expansion Tank will eliminate the 'cold sandwich' effect on tankless gas water heaters. I tried Googling and could not find anything on Act D'Mand, other than the gohotwater.com which appears to be a link farm. I did find Metlund has a Hotshot Dual Port that has a lot of the same features. Has anyone come across the ones by Act D'mand?
> 
> One thing I thought odd was the article stated "The typical life of an existing expansion tank is around one year on most residential homes."
> 
> ...


I can't speak regarding most manufacturers because I really only sell Noritz, but I really never have any problem with cold water sandwich, so for me, it doesn't seem necessary.

As for the 1 year life expectancy, I think this is simply marketing talk. Most thermal expansion tanks will have a one year warranty and that's probably what they base that statement on. I have seen all the things that MM points out but the truth is that a properly sized txt with a properly working prv will last for several years. The thing that seems to most often kill txts is a failed prv. Every txt I have looked at is only rated to 150 psi. At 150 psi the t&p takes over so it's not likely to exceed 150. 

The tank is what it is and it serves a good and useful purpose. Anybody can see this by simply connecting your pressure gauge to a wh drain that has no txt, turn the thermostat up until burner fires or element energizes, and watch the gauge. This tells the story every time. Now install the txt and repeat. The difference is obvious and immediate. 

Just don't ever sell a txt for the purpose of serving as the primary pressure regulating device. Run the tests to determine whether or not the prv has failed. I often sell both, sometimes one or the other but when you are talking about pressure issues, they are both absolutely linked.

P.S. the older a water heater is the more it needs a txt at least for gas wh this is true because if the wh has not been maintained (and none of them have been) there will be scale sludge in the bottom of the tank and the thermostat probe will also be scaled up (this in spite of the plastic sleeve over the probe). These two things combine to produce wide swings in the burner cycle (slow to fire and slow to shut off), which leads to overheating of water and the higher the temp is the more thermal expansion you have to deal with. Water heaters here are probably 95% gas and we have moderately hard water but elements in electric will certainly scale up to but not so on the thermostats so the problem is less pronounced on electric. Having said that, the IPC requires it and so we install txt on every replacement tank and often install txt on existing tanks.


----------



## Cal (Jun 17, 2008)

Strange ,,, we just DO NOT seem to be having a problem in our area with all this thermal expansion ,,,,,, yet . However ,, the exp tanks that i have seen ,,, have pretty much all failed . They are water logged or are rusting through . Maybe it's time for one of us to develop a new way !! $$$$$


----------



## garlandcmoney (Jun 9, 2010)

A.C.T bought out Metlund. The HotShot dual -port expansion tank is lined with a polypropylene food grade liner, so water never touches the tank walls. No rust! The threaded nipples are stainless. No rusting in place! The flow-through design and half-gallon capacity mixes the water to prevent the 'cold-water-sandwich', which happens when a tankless heater controls cuts itself off for a few seconds, but cold water is still flowing through the coils. This can happen with low flow, below the minimum allowed by the tankless controls, or by an interruption in water pressure. Imagine being in a shower where the water goes from 100F. down to 70F. This tank is the best on the market, for only a little more than a regular tank, with all their problems.


----------



## garlandcmoney (Jun 9, 2010)

Thermal expansion tanks are required by Code here in Pinellas County, Fla on all tankless. Florida Builders Code does not allow for using the t&p valve to compensate for thermal expansion. I have heard that all of California requires them, also.
If I were going to install one, it would be this HotShot, It has a liner thast stops water from ever touching the walls of the tank itself, plus it will drain completely, even when on its side, which regular tanks won't do. Plus, the nipples are stainless, so they don't rust in place and cause problems.


----------



## smellslike$tome (Jun 16, 2008)

Sniff, sniff, ... what's that I smell?


----------



## Protech (Sep 22, 2008)

Is that some local ordinance? That definitely isn't in the Florida state code and especially NOT for tankless heaters.

Why would you need a means of controlling thermal expansion on a tankless heater? The water is only heated when it is flowing which means it’s not a closed system. Thermal expansion control is only needed on tank type heaters because you are heating water in a static condition and in a sealed container (assuming you have some kind of PRV or backflow preventer on the water service.



garlandcmoney said:


> *Thermal expansion tanks are required by Code here in Pinellas County, Fla on all tankless*. Florida Builders Code does not allow for using the t&p valve to compensate for thermal expansion. I have heard that all of California requires them, also.
> If I were going to install one, it would be this HotShot, It has a liner thast stops water from ever touching the walls of the tank itself, plus it will drain completely, even when on its side, which regular tanks won't do. Plus, the nipples are stainless, so they don't rust in place and cause problems.


----------



## Optimus Primer (May 20, 2009)

garlandcmoney said:


> Thermal expansion tanks are required by Code here in Pinellas County, Fla on all tankless. Florida Builders Code does not allow for using the t&p valve to compensate for thermal expansion. I have heard that all of California requires them, also.
> If I were going to install one, it would be this HotShot, It has a liner thast stops water from ever touching the walls of the tank itself, plus it will drain completely, even when on its side, which regular tanks won't do. Plus, the nipples are stainless, so they don't rust in place and cause problems.


 
I have never put one on a tankless


----------



## Protech (Sep 22, 2008)

Do any work in Pinellas County? 


house plumber said:


> I have never put one on a tankless


----------



## Optimus Primer (May 20, 2009)

Protech said:


> Do any work in Pinellas County?


 
yep mostly


----------



## Protech (Sep 22, 2008)

So is garlandcmoney right?



house plumber said:


> yep mostly


----------



## Optimus Primer (May 20, 2009)

Protech said:


> So is garlandcmoney right?


I have never put one on a tankless. we use those pressure reliefs valves that look like a t & p valve without the probe. but no xpansion tank


----------



## Tankless (Jun 12, 2008)

It's a mixing tank basically. To help eliminate the God aweful "Cold water sandwich". I'm being sarcastic, because I don't thing it's a problem worth fixing....

PT is right, an XTX is not needed simply for a tankless, however I will still put them in on a closed system.


----------



## ROCKSTARPLUMBER (Dec 14, 2008)

personal tankless at my house, 6 months strong just about, not the first sandwich. How bout yours Rocksteady?


----------

