Replacing old Apollo Hydroheat 50ga. waterheater

hodge12

Replacing old nat. gas Apollo Hydroheat 50gal in improved 1,500sq ft. ducted basement. EnergyGuide reads: "First hour Rating 98 - Model(s) A5 50 65.ONQRT8 5FJ - Only models with first hour rating of 87 to 99 gallons are used in the scale." Got a good plumber but he's never even seen an old Apollo hydroheat system before viewing mine. He recommends an AO Smith with first hour rating 93 - Recovery rate 90degree = 67 - energy factor .058 at 65,000btu input. This GCVX50 is replaced by GCRX50L which has first hour rating 98 - Recovery rate 90degree=61 and energy factor .060 at 60,000btu input. Which one would work better or is there a water heater model better suited for replacement? Advice appreciated.

Also, just noticed on the Apollo heat exchanger that it states, "water coil: hot water only - max temp 190 max psi 100".

Abracadabra

I've stopped recommending any AO Smith product to my customers.

hot_rod

Unique to that tank was the high operating temperature control, and it had extra toppings to easily connect the hydro coil to the tank

Possibly other tanks would work, look for the btu capacity, temperature limit, and ideally extra connections

Paul48

He is using this for heat and DHW. I believe this is what he has. http://www.ableair1.com/pdf/apollo_brochure.pdf I believe their largest put out 55k for space heating. Maybe a combi-boiler?

Paul48

hodge12....You should take that water heater out of the title of your post. It's technically not just a water heater.

hodge12

New to site so I don't know where this reply will land. Thanks to all. Abracadabra: Have a Rheem upstairs but never have owned an A O Smith before, I'll do some more research.
Hot rod: You're right, on the heater it states: "High Energy Recovery Efficient Residential Gas - Not for use in mobile homes" It has a low, medium, hot and VERY HOT setting, but we keep it on low and it works well.
Paul: THAT'S IT, that's what I have!! I've seen that ad before a while back but had forgotten about it, thanks for posting it. I'll redo my title Paul, but if I don't call the Apollo a "water heater" what should I call it??

hot_rod

Bradford White has some high output tanks, snoop around there. State had a similar tank also

It is a combined system which makes some nervous, with a tank like the Bradford you could splt the system. Bock builds a tank with an upper heat exchanger inside

hodge12

Thanks again Hot rod. The plumber's shop is an A O Smith authorized dealer so we've concentrated on A O models, I'll check out some other Bradford, State and Bock.

Ironman

We've been using a combi boiler to replace old Appollos when the domestic load isn't too large. Probably any make and size of combi would be sufficient for space heating, but we need to know your domestic load for sizing.

How many baths do you have? How many people shower at the same time? Any unusually large domestic load such as a hot tub or George Jetson shower?

hodge12

Ironman: We have a 1981 3bed 2 bath, 1500sq ft wood frame sitting on a downward sloping paved neighborhood making for a large 10 ft brick high brick foundation/basement. Previous owner had basement fully excavated and installed 2 downstair bedrms, 1 bath with shower, kitchen, living room and a spa room was added. Total downstairs is another 1,500 sq ft making entire structure 3,000 sq ft. Upstairs is ducted and heated with gas furnace. Downstairs (basement) is fully ducted and heated with Apollo. 15 to 20% of downstairs is bordered by earth. Without heat in January it might hit as low as 45degrees. No room for gas line near existing duct work. You have an Apollo sending hot water in copper pipes 15 ft above narrow bathroom ceiling to heat exchanger closet located on other side of downstairs kitchen wall.
Little water use. Kitchen never, 2 people upstairs, kids now grown up and gone. Hot water used to heat space, provide maybe one shower a day, no kitchen use to speak of and the spa is empty, not used in years.

Paul48

Where are you located hodge12?

Ironman

Any combi with 3.5+ gpm domestic output @ 77* temp rise would probably be sufficient. Navien (lower end); Bosch GreenStar (middle); Veissmann (high end). Several others in the middle price range.

The input of any of these should be more than sufficient since the domestic load is much more than the space heating load.

4Johnpipe

Take a look at this put a few in so far...
http://www.htproducts.com/EFT_Combination_Floor.html
http://htproducts.com/EFT_Combination_Floor.html

hodge12

Paul: Located in Prescott, AZ about 5,600 ft above sea level. 45degrees the expected low tonight. We can get down to 12 degrees during the coldest winter.
Ironman: an A O Smith GCVX-50 100 series - First hour rating (GPH) of 93 - Gallon capacity of 50 - Recovery 90 degree F Rise Per Hour of 67 - Energy Factor 0.58 - Btu Input Per Hour Natural of 65,000 - R value of 16 was recommended to replace the Apollo.

hodge12

4Johnpipe: You must be a mind reader! Contacted a company today in Phoenix associated with HTP. They put me onto a local company and the tech was out of the office but will be calling me this week about the Phoenix light duty or other heating solution (they seem to deal with floor heating plus other hydro solutions. Possible overkill for my needs but the tech and I will talk this week. Thanks!

Ironman

hodge12 said:

Paul: Located in Prescott, AZ about 5,600 ft above sea level. 45degrees the expected low tonight. We can get down to 12 degrees during the coldest winter.
Ironman: an A O Smith GCVX-50 100 series - First hour rating (GPH) of 93 - Gallon capacity of 50 - Recovery 90 degree F Rise Per Hour of 67 - Energy Factor 0.58 - Btu Input Per Hour Natural of 65,000 - R value of 16 was recommended to replace the Apollo.

Most of that is not relevant as it deals with a tank heater and its storage. A combi boiler functions like a tankless heater and heats water on demand as it passes through it. There is no storage, therefore, they are rated in gpm output at certain temp rises. You have to be comparing the gpm at the same temp rise to know the output between brands. 77* is the number that will cover most situations and most manufacturers use it.

A standard water saver shower head will use a little less than 2 gpm of hot water for the average shower. Thus, a combi boiler or a tankless with a 3.5gpm output, will do one shower plus one other fixture running at the same time. That's continuous. If you need more than that, then look at a unit that has a 4-5 gpm output @ a 77* rise (or delta T).

Abracadabra

Read this if you are planning on going with an AOSmith. After seeing AOSmith's response to that situation I will never again recommend an AOSmith product to one of my customers.

http://forum.heatinghelp.com/discussion/154183/a-o-smith-water-heater-big-problems-no-help-johnny/p1

Paul48

The Phoenix light duty is a great water heater. But, you need a unit with 2 heat exchangers, like the product John linked to. What you have now, looks like a standard water heater, but it isn't. There is an additional copper coil in it, that acts as the heat exchanger for space heating. It is very important that the 2 systems be seperate. When you shut that heat off to the basement, the water becomes stagnant, and begins growing bacteria that could make you sick, or kill you.

hodge12

Paul: 2 hours ago I talked on the phone with an infloor heating specialist who I was referred to by contacting a contractor associated with HTP in Phoenix. He asked me EXACTLY what you just commented on - He's coming this week but told me to dig out the Apollo system manual and have it available so he can determine if the "water heater" (or whatever this Apollo is) has a separate coil in the tank to divide up household heating from the household water. He also mentioned bacteria growth as a concern. Cast iron versus stainless steel was mentioned (most of which went over my head) but he'll look at the whole system and tell me which way to go. The Light Duty Phoenix appears to be beyond what I would need for a 1,500 improved basement but he'll advise me further when he has a chance to go over how this old Apollo system is configured. I want thank you and all the people who have taken the time to contribute comments. I would have just rolled the dice and stuck a high recovery heater in without knowing if it would create problems for me.

Paul48

Oh boy......I'll correct myself.....Evidently, your system does not have a seperate heat exchanger for space heating. Look at "How our system works". This would be why they are no longer made.
http://www.ableair1.com/pdf/apollo_brochure.pdf

Henry

It is a combo certified hot water tank that is designed only to work with an air handler and nothing else. The stagnant water in the rest of your system is dangerous to everyoones health. The minimum temperature for a storage tank is 140F to kill the legionnair bacteria. Yours at minimum is below this and your risks are exponential.

hodge12

Sooooo we've been kept alive all these years because the heater has been rated at "water coil: hot water only - max temp 190 max psi 100"???? That quote is from the tank along with the rating of 65,000 btu's. Damn, this is not sounding good. Luckily the only use for domestic has been an occasional shower and boiling water from the tap on the stove down there! I'll be printing all this out guys and showing it to the fellow coming over this week!

wogpa67

I've seen good companies that installed these with a timer on the circulator to keep the water from becoming stagnant.

Myself I don't install open systems.

hot_rod

If you do want to separate the DHW from the heating water this might be a good option.
http://www.bockwaterheaters.com/Portals/0/productfiles/80026_Rev11-13_EZPDV-C.pdf

Also if you go with a higher efficiency heater you will probably need a different venting system, I suspect yours has a metal "B" vent system,. High efficiency equipment needs to vent with plastic or stainless materials.

This product is probably priced between the various tank type combined heaters that Bradford White offers and the condensing type high efficiency units out there.

This gives you the piece of mind of separation between the two systems. Most plumbers prefer to keep the fluids separated.

hodge12

Thanks to all for the further comments - I'll be printing all the links of what have been referenced to show the gentlemen who is coming to look at the "Circulating Loop-Space Heating Gas-Fired Water Heater" Dug out the install / manual and that is what the Apollo was called by the vendor.

aishaelizabeth

Hey Hodge! I was just wondering what water heater you used to replace the Apollo. I have an Apollo system in my home (I live in Chino Valley) and I'm having trouble finding someone who knows anything about the Apollos.

Thanks!