In search of installation advice

Alexr54

Well-known member
Jun 17, 2015
66
Florida
#1
I just got a new pool heater to replace my old rusted broken one. Is been down for almost a year now. The new heater is a completely different brand and I was hoping to possibly get a bit of installation advice and tips.

I have a Hayward aqua plus pro logic control board which everything goes into. I can get the model if it helps.

My old rust bucket heater is a raypak 266k btu. It's the old model with a manual knob and toggle off/on switch. It totally rusted out at the bottom and stopped firing. All advice I got was to replace the junk heater.
My new heater is a pentair sr400lp (Sta-rite Max-E-Therm 400). Looks like a fancy heavy garbage pail [emoji3]

The control board always controlled my heater (when it used to work), turning it off and on using the remote control. I would like to keep it that way if at all possible.

Just to be safe I also ordered 2 new thermostats.

My system has 2 pumps. One for the hot tub and one for the pool. There is thermostats in both pipes. It's also a salt water pool with a Hayward t15 salt cell.
Currently the spa pump (2 1/2hp) is piped into the heater. I will keep it that way. The spa has an overflow to the pool.

Does anyone know the best way to hook up the new heater to replace the old one while working in the same way? (Through the control board)
I've never messed with the board yet except to change settings on it, like timers and salt chlorination level settings. I do know how to go into the 'advanced mode'. But I have never done anything with the wiring.

Preferably I would like to set it up to heat both the pool and hot tub. Not sure if that's possible. If I can somehow plumb each pump through the heater. I don't know.

Installation tips are very much appreciated.
Anything particular that I should look for which changes from the old heater to the new one?
Are the propane fittings the same type? Anything there I should keep an eye on?
Any particular tools I should get which aren't in the regular tool box? Any tips on putting the heater on a base stand or something? This new heater is not supposed to rust but I would rather have it raised anyway, just from bad experience. The old heater was directly on a concrete slab that was soaked in water anytime it rained. The new heater will go on that slab as well.

Any advice and tips like that would help me tremendously to tackle this installation with a better success rate then I anticipate.

I would like to do this installation myself so I have a better understanding of my own stuff and to know better what to look for when issues arise.

I'm excited to get the heater up and running!!! My hot tub awaits!!!


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Alexr54

Well-known member
Jun 17, 2015
66
Florida
#3
Alex,

I suspect your old heater had two or three wires going to it from your automation system. You should be able to connect these same wires to your new heater.

See pages 29 and 30 of your heater manual.. See this... http://www.pentairpool.com/pdfs/MaxEThermEng.pdf

Thanks for posting,

Jim R.
Thanks. My old heater is still in place and I have not yet disconnected any wires. I'm not sure yet what is there. Did this to make sure I don't miss anything. I plan on disconnecting only when I'm going to install the new one right after. And will take many pictures during the disconnect process.

I will definitely take a very close look at what you provided. Thanks!!


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Jimrahbe

Mod Squad
TFP Expert
LifeTime Supporter
Jul 7, 2014
10,885
Bedford, TX
#5
Alex,

If your old system used a two-wire cable, then it should work.

If your old system used a three-wire system, you just have to make sure which wire goes to what connection as shown by the manual.

I suggest that you take a close up picture of the connections inside the old heater before removing the control cable...

Jim R.
 

Pool Tool

Well-known member
May 15, 2014
757
Western Chicago Area, IL
#6
I just installed a Raypak heater to be controlled by the same automation system...well last year. The Aqua Plus (AP) will control the heater via one of the relays, but it doesn't power the heater through the relay. Basically the heater will always have power but will only turn on when the AP set point is reached. On the Raypak, I just had to complete the wiring per the owners manual then set the heater to 'remote control' by holding down a few buttons for 5 seconds. It was all detailed in the owners manual. Seems a little daunting, but was pretty simple in the end.

The AP does have both SPA and Pool temperature set pts based on what mode you are running in. That assumes both are piped through the heater though. Your setup sounds a little different, since currently you can heat your pool independent of your spa correct??
 
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Alexr54

Well-known member
Jun 17, 2015
66
Florida
#7
Thanks for the great information.
Currently my setup allows me to only heat the spa independently, or heat both the spa and pool using the spillover function from the spa.
Eventually I would like to be able to heat both independently but that would require a good amount of new plumbing and another jandy valve.

My system also has a Polaris in ground cleaning system (which is on the fritz). It's as complicating as it gets.

I'm curious to see how much more gas my new 400k heater eats up compared to my old 266k unit.




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pooldv

Mod Squad
TFP Expert
Platinum Supporter
LifeTime Supporter
Aug 10, 2012
24,993
DFW, TX
#8
A larger heater won't use more gas than a smaller heater. It takes the same number of BTUs to heat a body of water a certain number of degrees. A larger heater will just do it faster.
 
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Alexr54

Well-known member
Jun 17, 2015
66
Florida
#9
A larger heater won't use more gas than a smaller heater. It takes the same number of BTUs to heat a body of water a certain number of degrees. A larger heater will just do it faster.
That's interesting. I didn't know that.
So why would anyone get a smaller btu heater? The price is not that much of a difference.


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Pool Tool

Well-known member
May 15, 2014
757
Western Chicago Area, IL
#10
Larger heaters are claimed to be slightly more efficient (read slightly) than their smaller counterparts, but pooldv is right. It will use twice the gas, but do it in half the time. And it's how quick you can heat that matters, so I think you'll enjoy the larger one.

- - - Updated - - -

Sometimes it a fuel supply issues (pressure and volume) that keep people with a smaller one, but really pad size, upfront cost or just misinformation.
 

ps0303

TFP Expert
In The Industry
Jul 6, 2011
3,959
FL
#11
For hooking it into your controller, look in the manual on page 29. You have a two wire option and a three wire option.

In case you don't have the manual.

http://www.pentairpool.com/pdfs/MaxEThermEng.pdf

Also, you will be making PVC piping changes, as well as your gas line needs to be modified. So get some PVC, PVC fittings, and any gas pipe you need. Yo will also need the correct thread sealant for the gas pipe. You'll need elbows, variosu lengths etc. So map it out and maybe you can get by with one maybe two trips to get the pieces you need.
 
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Alexr54

Well-known member
Jun 17, 2015
66
Florida
#13
I would just like to thank all of you once again for your great advice!
So far the installation has been lots of work, especially the maze of plumbing required to fit the new heater compared to the old one.
The gas line and power was the quickest part so far.
Today I will be finishing the plumbing. Everything was cut and put in place without cement. Today I will make sure all cuts are straight and clean, then start cementing them together.
Then the real test...

So far power and gas is good. No gas leaks. And I was able to turn on the heater. It had the check system light on. Which I guess is expected since there is no water in it yet.

I went with the 120V setup, I didn't see why a 240V would be beneficial with a propane heater.


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ps0303

TFP Expert
In The Industry
Jul 6, 2011
3,959
FL
#14
I went with the 120V setup, I didn't see why a 240V would be beneficial with a propane heater.


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Having the ability to do either is what all units are these days. Mostly because lots of installers hook it into the timer where the pump is and that can be either 120 or 240. Doesn't matter what type of gas your system uses with regards to the electrical connection.
 

JamesW

TFP Expert
Mar 2, 2011
13,049
#15
Assuming the same efficiency, a smaller heater will use more gas getting to set point than a larger heater.

That's because the pool begins losing heat as soon as you turn on the heater. If a smaller heater takes twice as long to heat to set point, you're losing heat for twice as much time.

For example, assuming two identical pools, , if a smaller heater took two days to reach set point and a larger heater took one day, the pool will lose heat the entire first day. After the first day, the smaller heater will be 1/2 way to set point. Then the larger heater begins.

The larger heater will not catch up to the smaller heater until the end of the second day.

Once the heaters reach set point, the heat cost is the same.

During the heat up time, the larger heater pool is always cooler than the smaller heater pool until they reach set point. That means that the smaller pool is losing more heat than the larger pool during heat up.

Also note that the larger heater requires larger gas line and a larger propane tank than a smaller heater.

The larger tank is to provide more surface area of the liquid propane in contact with the container walls and open surface area above the liquid propane.

The liquid propane needs to boil and become a gas. To do this, the liquid needs to absorb heat from the tank walls and the walls need to absorb heat from the air (if above ground) or from the earth if below ground.

Your old heater might be ok with a 250 gallons tank, but your new one will need closer to 500 gallons.

Having an undersized tank can result in frosting of the outer tank surface as the liquid absorbs heat from the tank walls. The walls can get too cold causing condensation and if cold enough, the condensation can freeze. Frosting of the tank reduces it's ability to absorb the heat needed to boil the liquid into gas.

For a 500 gallon tank, assuming that the usable volume is 300 gallons (80% max fill to 20% recommended minimum fill), a 400,000 btu/hr heater can run about 68.5 hours on a full (80%) tank.
 
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Alexr54

Well-known member
Jun 17, 2015
66
Florida
#16
Ok so I got everything hooked up. The heater turns on when it's supposed to using the aqua logic control panel but it's blowing cool air only...
I'm stuck


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Alexr54

Well-known member
Jun 17, 2015
66
Florida
#17
Scratch that. It was a gas toggle switch I forgot to put on. Doh!!!

Working great now. Just need to adjust a few settings so it can run on the spa pump on alone. Currently for some reason it only turns on with the pool pump on.

Adjustments done. Looks like that's it for now. Thanks all!

Btw I have a 250g tank. It works without issues.
I'm in Florida so cold is not too much of an issue here.


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JamesW

TFP Expert
Mar 2, 2011
13,049
#18
250 gallons might do ok in warmer weather. 500 would be preferred. Cold weather installation would probably require 500 gallons.
 
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Alexr54

Well-known member
Jun 17, 2015
66
Florida
#19
It took about 10 minutes to heat my hot tub from 70 to 90.
Couldn't ask for better.
I also was watching my gas meter. It didn't even tick down 1%.


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JamesW

TFP Expert
Mar 2, 2011
13,049
#20
A 400,000 btu/hr heater will use about 4.37 gallons of propane per hour. To convert 4.37 gallons of liquid propane into propane gas, the liquid needs about 3,379 btu. So, the liquid has to absorb 3,379 btu/hr from the ambient environment to provide enough gas for a 400,000 btu/hr heater.

When the tank is filled, the propane boils until the pressure above the liquid is sufficient to prevent further boiling. As the gas valve opens, the pressure in the tank falls, and the propane liquid begins boiling. As the propane boils, it loses heat to the gas. To continue to create more gas, the liquid needs to get 3,379 btu/hr (990 watts) from the ambient environment.

The main factors in supplying enough gas include surface area of propane liquid in contact with the tank walls, ambient temperature, humidity and load in btu/hr.

The worst case would be low fill percent of tank, very low ambient temperatures, high humidity and long continuous heater run time.

Under good conditions, you will probably be ok. Under adverse conditions, the gas pressure might become an issue.