On Demand hot water systems 2nd post

[bobbyb]

Second Post, nhboy is filling up the hot topic forum again.

I am trying to decide whether to replace the existing system with a new tank or an electric on-demand system. My house is to total electric. I am familiar with how both tanks and on-demand systems work. What I am looking for is someone on SOMD that has had experience with on-demand electric hot water systems. There seems to be some talk on some of the other forums i.e. doityourself.com and others that on-demand electric systems may not be up to snuff and that gas is the only way to go. At some point, upgrading to propane (no gas available) costs way too much to make the whole upgrade worthwhile, even with the tax advantages.

 

[itsbob]

Second Post, nhboy is filling up the hot topic forum again.

I am trying to decide whether to replace the existing system with a new tank or an electric on-demand system. My house is to total electric. I am familiar with how both tanks and on-demand systems work. What I am looking for is someone on SOMD that has had experience with on-demand electric hot water systems. There seems to be some talk on some of the other forums i.e. doityourself.com and others that on-demand electric systems may not be up to snuff and that gas is the only way to go. At some point, upgrading to propane (no gas available) costs way too much to make the whole upgrade worthwhile, even with the tax advantages.

I'd rethink the affordability of the gas option.

I know I converted to a gas water heater in my home in NH, and the gas company provided the gas tank, and the free install. They are looking at you as a LOONNG term customer, and the possibility of additional gas appliances in the future IF they can make it worthwhile for you to convert an appliance to gas. Worst case is they lease you the tank for about $5 a month.. free install of new appliance.. and scheduled re-fills on the gas tank.

LOWE's has some tankless water heaters in their store. I'm not sure if they were gas or electrcic, and it's probably a special order.. but they are one way to go.

My parents have a tankless water heater in their house and LOVE it, but again I think it's a gas tankless.. Cheap, cheap compared to the cost of Electric in NH.

 

[bobbyb]

I'd rethink the affordability of the gas option.

I know I converted to a gas water heater in my home in NH, and the gas company provided the gas tank, and the free install. They are looking at you as a LOONNG term customer, and the possibility of additional gas appliances in the future IF they can make it worthwhile for you to convert an appliance to gas. Worst case is they lease you the tank for about $5 a month.. free install of new appliance.. and scheduled re-fills on the gas tank.

LOWE's has some tankless water heaters in their store. I'm not sure if they were gas or electrcic, and it's probably a special order.. but they are one way to go.

My parents have a tankless water heater in their house and LOVE it, but again I think it's a gas tankless.. Cheap, cheap compared to the cost of Electric in NH.

That is good advice I was looking at the electrical requirements for the on-demand electrical system and they are horrible:

PowerStar AE125 requires 240/220 Volts and draws 120 Amps (3 x 40 Amp Breakers) when providing hot water. It has a 95% efficiency rating. It can provide 3.7 gallons per minute for water usage at 105°F* - 2 sinks simultaneously or 1 shower or bathtub. It can provide 3.0 gallons per minute for water usage at 115°F* - 2 sinks simultaneously or 1 dishwasher.

That means I would have upgrade the distribution box and get another line in from SMECO.

 

[itsbob]

Rheem sells a propane tankless for $800.. 8.4 GPM (a shower uses about 2.5 GPM). It's thermo controlled from 100 - 140 degrees.

I'd call the local gas companies and see what kind of deal they can make you. That's my plan when it comes time to replace our current waterheater.

Residential gas models are available that can heat more than five gallons per minute by 60°F, generally more than enough for two showers to be run simultaneously. Whole house electric units typically have a capacity closer to three gallons per minute.

 

[bobbyb]

Good idea, thanks Bob.

Bob

 

[Dougstermd]

That is good advice I was looking at the electrical requirements for the on-demand electrical system and they are horrible:

PowerStar AE125 requires 240/220 Volts and draws 120 Amps (3 x 40 Amp Breakers) when providing hot water. It has a 95% efficiency rating. It can provide 3.7 gallons per minute for water usage at 105°F* - 2 sinks simultaneously or 1 shower or bathtub. It can provide 3.0 gallons per minute for water usage at 115°F* - 2 sinks simultaneously or 1 dishwasher.

That means I would have upgrade the distribution box and get another line in from SMECO.

E-Bay has some really good deals on Tankless heaters. The biggest concern/cost would be the need to run those three circuits. Just the material alone will add a considerable cost to the overall project. I work with a guy who has a tankless heater and he is very happy with it. I am planning on putting one in my house right after closing.

 

[Dougstermd]

CHECK THIS ONE OUT




less than $200 and free shipping:shrug:

 

[Mikeinsmd]

That is good advice I was looking at the electrical requirements for the on-demand electrical system and they are horrible:

PowerStar AE125 requires 240/220 Volts and draws 120 Amps (3 x 40 Amp Breakers) when providing hot water. It has a 95% efficiency rating. It can provide 3.7 gallons per minute for water usage at 105°F* - 2 sinks simultaneously or 1 shower or bathtub. It can provide 3.0 gallons per minute for water usage at 115°F* - 2 sinks simultaneously or 1 dishwasher.

That means I would have upgrade the distribution box and get another line in from SMECO.

Because it takes 3 - 40 amp breakers doesn't mean it'll pull 120 amps. 80% of that at the very MOST. You're still looking at an exorbitant electric bill.

Why is this so important?

 

[Dougstermd]

Because it takes 3 - 40 amp breakers doesn't mean it'll pull 120 amps. 80% of that at the very MOST. You're still looking at an exorbitant electric bill.

Why is this so important?

it only runs when you use hot water elsewise its dormant. so the electric bill should be cheaper cause you are not keeping 40 gallons of water hot 24/7.

 

[bobbyb]

It only heats the water when you need it and saves you a lot of money on your electric bill, and has tax advantages. But the startup costs are a big deal.

There are some big differences in performance of different brands and models. So you could very easily spend a great deal of money and have very little hot water or as some people are saying just warm water.

 

[Mikeinsmd]

it only runs when you use hot water elsewise its dormant. so the electric bill should be cheaper cause you are not keeping 40 gallons of water hot 24/7.

It only heats the water when you need it and saves you a lot of money on your electric bill, and has tax advantages. But the startup costs are a big deal.

There are some big differences in performance of different brands and models. So you could very easily spend a great deal of money and have very little hot water or as some people are saying just warm water.

Ahhhhh..... ok.

 

[Dougstermd]

also the units are much smaller than conventional water heaters.

 

[bobbyb]

also the units are much smaller than conventional water heaters.

And some of the models are designed to mounted outside the house.

 

[Cletus_Vandam]

I'd stay away from the ebay special deal on this one. Even though it says it made in the USA, it could be garbage and once you get it, it's yours. This is the kind of thing that could easily become a fire hazard, even it wired correctly.

If you are interested in DIY installation, give RE Michael's a call or stop in and talk to one of the guys at the counter. They will give you an idea on what works the best and what they have had the least amount of return or problems with.

Also, on the topic of tank style water heaters, if you go that route go for the highest efficiency you can find and add the outer blanket insulation wrap to help keep the stored heat contained.

As for getting the local gas companies to "give" you a propane tank. Good luck! When I built my house five years ago I called several companies and they all were the same. "Sure we'll sell you an underground tank" or "Sure we'll rent you an above ground tank". Take your pick. There aren't any other options. The rent they charge is added to the gallon per fill charge. Not too costly, but the long run you'll pay for the tank and keep paying.

 

[Cletus_Vandam]

Almost forgot

If you do go the propane route, be sure to think about the routing for the exhaust stack and combustion air make-up. You'll need both.

 

[bobbyb]

Thanks guys, all good advice.

Keep it coming. I can see some pit falls I need to be careful about.

 

[czygvtwkr]

A good electric water doesn't use that much. My 50 gallon is set at 120 and uses about $35 a month. If you are looking for energy efficient electric hot water heaters take a look at the electric heatpump water heaters. Until the end of the year there is a tax credit for installation of one.

 

[Dougstermd]

I'd stay away from the ebay special deal on this one. Even though it says it made in the USA, it could be garbage and once you get it, it's yours. This is the kind of thing that could easily become a fire hazard, even it wired correctly.

tank and keep paying.

If they are the same model and make, it will be the same product.

Also many newer hotwater heater specifically state NOT TO USE and insulation blanket.

 

[czygvtwkr]

If they are the same model and make, it will be the same product.

Not necessarly, there are a lot of Chineese knock offs on ebay. There are even items with fake UL approved stickers on them.

 

[Dougstermd]

Not necessarly, there are a lot of Chineese knock offs on ebay. There are even items with fake UL approved stickers on them.

just as with anything else I guess:shrug:

I will still most likely buy mine on E-Bay