Side Arm VS. Plate exchanger

[Medman]

Hello again,
First off let me say I love this site. I am changing out my water heater which now is a fuel oil rheem, with a side arm from my owb. I am going to an electric water heater for convenience.
Last year I burned approx 200gal of fuel oil just to heat water when my owb was not burning owch.
My question is should I keep the side arm or would a plate exchanger work better, by better I mean faster recovery?
Which one is better?
Thank you
Tim

 

[Dirttracker]

I'd say go with a plate, but I'm biased as that's what I have. I've used a 16 plate HX since 2003 with good results. For the first 5 years I had it in series on the inlet to my LP water heater. I'd shut the water heater off when I was operating the boiler. I never had a problem. But if it sat for a long time with no demand, I'd have to run the hot water for a couple of minutes to get hot water flowing. Since 2008 I've had the plate HX operating by iteslf (like a tanless water heater). The 16 plate has been good enough to feed a single hot water demand as long as my boiler water temps are over 150. I'd suggest using a tempering valve on HX oulet if you go tankless, otherwise the domestic water temp can get pretty hot with low flow.

One other thing, a plate is not the way to go if you have hard water. You'll plug up the plate in short order unless you give it soft water. I had my softener go out for acouple of months and it almost plugged the HX completely. They can be flushed using acid to remove the fouling, but then you have to take the HX out - not something to do on a regular basis.

 

[upsnake]

The plate is going to give you more water, as all incoming water would be hot.

The argument for the side arm, is that the water would cool down in the tank after going through the plate. (which i have not found to be a problem).

I have mine going through the plate into the tank. I saw some recommendations to just run the plate with out the tank, but i like the tempering effect of the tank.


Anyway the plate has worked great for me, unlimited hot, and it stays hot between usage.

 

[blackdogon57]

Don't forget tank size. I went to a 60 gallon electric with a huge side arm. I have virtually unlimited hot water with the breaker off.

 

[Medman]

Don't forget tank size. I went to a 60 gallon electric with a huge side arm. I have virtually unlimited hot water with the breaker off.

How big is "hugh" My side arm outer copper is 2" and its appox 4' in length.
I think my issue is volume my heater now is only 32gal which makes the heater kick on due to lack water in the tank, if that make since.
Tim

 

[oneoldbanjo]

I have a 60 gallon water heater with both a plate exchanger and a sidearm. I was not a member of this site at the time and I did not know which "one" to do.....so I did both.

After living with the system for 3 years, I believe that the plate exchanger alone would be plenty. I knew the plate exchanger would heat the water coming in - but I was afraid that it would cool off in the tank if we failed to use water often. It turns out that we have to be gone for about 3 days before the water in the tanks becomes cool.

If you get only one........get the plate exchanger.

 

[deutzman]

I use a 20 plate exchanger and no tank. As long as there's wood in the CB there's always hot water. I can run hot water 24 hours a day and never run out. Last year on April 15th I had family members here because my Dad passed on the 13th. Had 7 take showers back to back and the water was just as hot on the last shower as the first. Plate exchangers are are as simple as it gets and work great. I even have mine located in a building beside the house. Best hot water system I've ever had. And I had a Rheem tankless that was good.

 

[Laird]

I have no experience with a sidearm, but I have no complaints with the plate exchanger other than Liming up. I choose not to soften my water so I bought a second plate exchanger and swap them out once a year. I run vinegar through it several times and it's good to go again.