Storage aquastat

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toothy

Member
May 7, 2009
14
Seward Alaska
Hello All

My storage tanks, 2 x 500 gallon propane, are standing in the basement and in need of an aquastat. I have a Tarm Excal 2000 and their diagram says to use a Honeywell L8151A, they don't seem to be available anymore.

I cross referenced it on the Honeywell site and came up with a L7224U1002. It is a bit fancy looking for my taste, I can barely handle simple.

If that is what you all think I should use I'll give it a whirl. If however you have a different solution I'm all ears.

Thanks
Wade
 
What is the aquastat on the storage for ? I don't have one on mine.
 
The aquastat on storage is probably used to only operate the heat distribution system when the storage if hot enough to provide heat and allow for a backup to take over. I like the Johnson Controls A419 but it is more complex than the one your Tarm diagram mentioned. What is nice it the digital readout on the A419 gives the actual temperature and lets you set everything from the keypad. At about $50, I think I picked it up for less than what the old style Honeywell's went for plus I have an accurate temp reading to boot. They are well built, durable, and come in 24V and 120V versions allowing them to be powered by whatever source is handy. http://www.pexsupply.com/A419-Series-Temperature-Controls-10146000?gclid=CL_iuNrpiq8CFQvGKgod_z0d9Q
 
Woodsmaster

The reason for the aquastat is as rkusek described.

rkusek

The one Tarm calls for the L8151A is only available OEM @$325. I think it does things the A419 doesn't, but I could be way wrong. The Honeywell "provides high limit, low limit, and circulator control".

The weird thing is the one on the side of the boiler an L8124A, C seems to do the same stuff and below the L8124A,C it says L8151A. I know just enough to be dangerous!!

Thanks for the help
Wade
 
The aquastat on storage is probably used to only operate the heat distribution system when the storage if hot enough to provide heat and allow for a backup to take over. I like the Johnson Controls A419 but it is more complex than the one your Tarm diagram mentioned. What is nice it the digital readout on the A419 gives the actual temperature and lets you set everything from the keypad. At about $50, I think I picked it up for less than what the old style Honeywell's went for plus I have an accurate temp reading to boot. They are well built, durable, and come in 24V and 120V versions allowing them to be powered by whatever source is handy. http://www.pexsupply.com/A419-Series-Temperature-Controls-10146000?gclid=CL_iuNrpiq8CFQvGKgod_z0d9Q
I See. I don't have backup so that's why I don't have one.
 
I have an A419 on my tank and it seems to do the trick. Pretty easy to setup and the readout tells me where my tank is temp wise.

K
 
Woodsmaster

The reason for the aquastat is as rkusek described.

rkusek

The one Tarm calls for the L8151A is only available OEM @$325. I think it does things the A419 doesn't, but I could be way wrong. The Honeywell "provides high limit, low limit, and circulator control".

The weird thing is the one on the side of the boiler an L8124A, C seems to do the same stuff and below the L8124A,C it says L8151A. I know just enough to be dangerous!!

Thanks for the help
Wade
Post a link to that Tarm schematic. I doubt that Honeywell is doing anything that the $50 JC won't do plus you will know exactly what your temp is whenever you want.
 
Hello All

My storage tanks, 2 x 500 gallon propane, are standing in the basement and in need of an aquastat. I have a Tarm Excal 2000 and their diagram says to use a Honeywell L8151A, they don't seem to be available anymore.

I cross referenced it on the Honeywell site and came up with a L7224U1002. It is a bit fancy looking for my taste, I can barely handle simple.

If that is what you all think I should use I'll give it a whirl. If however you have a different solution I'm all ears.

Thanks
Wade


The L7224U is an electronic aquastat control for a boiler usually with an oil burner. Are we replacing the existing aquastat on the boiler?
 
I just bought an L8124A, C L8151A on e-bay and maybe it will work, or I have more scrap laying around. The spec's and functions look the same, I'll find out. Do you think they put 2 numbers on the same aquastat just to irritate and confuse folks?

Thanks
Wade
 
Call me old fashioned but I still like the old style electro/mechanical style controls better than the printed circuit board electronic type. Lots of those old controls out there at 30-40 years old and still functioning after hundreds of thousands of cycles.
JMHO.
 
Here is a link to their schematic http://woodboilers.com/admin/uploads/public/WoodBoilerPlumbingSchematic1110Web(1).pdf I believe page 31 is what I'm trying to do. No I'm not replacing an aquastat I'm adding storage.

I looked at the wiring diagram on page 31, it's wired to the low voltage side, assuming all the terminals on that 24v strip are really 24v.
I'm not sure why they would use a line voltage control on the low voltage side. Any aquastat with L1, ZR and B1 should work. I didn't see
any listing for the limit and differential settings on the control.
 
I do believe all the terminals on that strip are all 24v, their kind of hanging out there for kids to stick their tongue's on. Also the guy at Tarm said something about not using the new L7224U1002 because you didn't need line voltage, or something fairly close to that.

As I said I bought a aquastat that says L8151A , and other things on it, so I'll hope for no external to boiler magic smoke. I'm probably missing something, but it wouldn't be the first time.

Thanks
Wade
 
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