descaling commercial big heaters - Plumbing Zone

Protech · 08-16-2010, 03:42 PM

I don't do much commercial but I just received a call from a hotel about their AO smith cyclone Xi heaters. They are BTH 250 models and they have not been descailed yet. They are about 2 years old and the water is quite hard in this area.

Questions:

What deliming solutions would you recommend?

How long does it usually take to delime once onsite in front of heaters with tools in hand per heater?

How do I get the coil clean? Filling the whole tank with solution seams very slow and would use quite a bit of cleaning solution. Maybe a flexible sprayer wand?

ckoch407 · 08-16-2010, 03:46 PM

Quote:

Originally Posted by Protech

I don't do much commercial but I just received a call from a hotel about their AO smith cyclone Xi heaters. They are BTH 250 models and they have not been descailed yet. They are about 2 years old and the water is quite hard in this area.

Questions:

What deliming solutions would you recommend?

How long does it usually take to delime once onsite in front of heaters with tools in hand per heater?

How do I get the coil clean? Filling the whole tank with solution seams very slow and would use quite a bit of cleaning solution. Maybe a flexible sprayer wand?

Ive never done a cyclone but I have done some of the old copper coil, brass fin, and storage tank ones. I think it was Calci-Solve, and Ive heard of people using Clobber with a proper dilution. I would go online and double check the manuals though.

Protech · 08-16-2010, 03:59 PM

Will Calci-solve or clobber damage the lining?

I was just reading about "rydlyme". Seems like a good choice. The only thing I'm unsure about is how to clean the big coil that is way above the hand hole. I was thinking about those hand pumped sprayers that the pest control guys use. I could just bend the pole that goes to the sprayer so that it could reach up into the tank and spray the coil off. What do you think?

I suppose I could just fill the whole tank with a diluted solution but that would take a long time and use a whole lotta chemicals. Maybe pour in a few gallons on concentrated solution thru the hand hole. Then pump in RO water from some pre-filled trash cans to dilute. That way it gets everywhere. Seems like it would take a long time and they do NOT want lots of down time. The heaters cannot be drained separately as there are no isolation valves on the outlet manifold, only the inlet.

go online and double check the manuals though.[/quote]

ckoch407 · 08-16-2010, 04:11 PM

Quote:

Originally Posted by Protech

Will Calci-solve or clobber damage the lining?

I was just reading about "rydlyme". Seems like a good choice. The only thing I'm unsure about is how to clean the big coil that is way above the hand hole. I was thinking about those hand pumped sprayers that the pest control guys use. I could just bend the pole that goes to the sprayer so that it could reach up into the tank and spray the coil off. What do you think?

[/QUOTE]

Not sure bout the cyclones, but thats what the manual used to recommend... filling the tank with diluted hydrochloric acid for those dinosaurs. It probably would do damage if you sprayed it right on the coil. Bad comparison on my part... apples oranges.

Protech · 08-16-2010, 04:21 PM

They want to sell me their proprietary "un-lime" solution which is special order and they charge a premium.

Do you think it would hurt the lining if I just filled the tank with hydrochloric acid diluted with RO water 1 parts to 5 parts and then kicked the burner on until the solution was about 120F? The tanks heat to that temp in about 5 minutes.

Not sure bout the cyclones, but thats what the manual used to recommend... filling the tank with diluted hydrochloric acid for those dinosaurs. It probably would do damage if you sprayed it right on the coil. Bad comparison on my part... apples oranges.[/QUOTE]

Colgar · 08-16-2010, 04:49 PM

Going from memory here.....

AO Smith wants the anodes pulled before deliming

If you pull the access cover, have a new gasket, new bolts, drill and tap handy.....

SewerRatz · 08-16-2010, 05:47 PM

The reason they want the anode rods pulled before deliming a heater is the acid used to delime the heater and the magnesium anode rod will produce large quantity of hydrogen.

Unlime is the best out there, it uses phosphoric acid (same stuff in soda pop) and washes out of the heater easily and does not do any damage to the heater or pipes.

The local supply here sells Unlime by the gallon for 25 bucks if I recall might be a bit more than that. It has been a while since I priced the stuff. It is cheaper to get it in the 5 gallon jug though.

Protech · 08-16-2010, 08:53 PM

Why not just phosphoric acid? The problem with these heaters is that they have a spiraled flame tube that is up high above the hand hole. I can scoop the scale out of the bottom but the stuff stuck to the flame tube is not easily accessible. The anodes are DC powered anodes and do not need to be removed during deliming. These heaters are only about 2 years old so they shouldn't be too bad.

I think the thing to do here is sell them some isolation valves on the outlets so that each heater can be isolated and drained individually. That way I can just truck in 2 55gal drums of RO water and a few gallons of phosphoric acid. I can just mechanically remove most of the scale and then fill the heater up with the RO water/phosphoric acid mix and let it sir for a day. Come back the next day and do it all over again with the next heater.

What do you think?

Farmtek · 08-16-2010, 11:07 PM

That rydlime is a good product that works.

SewerRatz · 08-16-2010, 11:21 PM

Quote:

Originally Posted by Protech

Why not just phosphoric acid? The problem with these heaters is that they have a spiraled flame tube that is up high above the hand hole. I can scoop the scale out of the bottom but the stuff stuck to the flame tube is not easily accessible. The anodes are DC powered anodes and do not need to be removed during deliming. These heaters are only about 2 years old so they shouldn't be too bad.

I think the thing to do here is sell them some isolation valves on the outlets so that each heater can be isolated and drained individually. That way I can just truck in 2 55gal drums of RO water and a few gallons of phosphoric acid. I can just mechanically remove most of the scale and then fill the heater up with the RO water/phosphoric acid mix and let it sir for a day. Come back the next day and do it all over again with the next heater.

What do you think?

UnLime is 99% phosphoric acid. So I do not see an issue.

08-16-2010, 03:42 PM	#1
Protech ٩(͡๏̯͡๏)۶ Join Date: Sep 2008 Location: Polk County, Florida Posts: 7,167 My Photos	descaling commercial big heaters I don't do much commercial but I just received a call from a hotel about their AO smith cyclone Xi heaters. They are BTH 250 models and they have not been descailed yet. They are about 2 years old and the water is quite hard in this area. Questions: What deliming solutions would you recommend? How long does it usually take to delime once onsite in front of heaters with tools in hand per heater? How do I get the coil clean? Filling the whole tank with solution seams very slow and would use quite a bit of cleaning solution. Maybe a flexible sprayer wand? __________________ Plumber, Repiping, Replumbing, Leak Detection, Solar Water Heater, Drain Cleaner, Pipe Leak, Polk County Plumber, Lakeland Plumber, Winter Haven Plumber, Haines City Plumber, Bartow Plumber

08-16-2010, 03:59 PM	#3
Protech ٩(͡๏̯͡๏)۶ Join Date: Sep 2008 Location: Polk County, Florida Posts: 7,167 My Photos	Will Calci-solve or clobber damage the lining? I was just reading about "rydlyme". Seems like a good choice. The only thing I'm unsure about is how to clean the big coil that is way above the hand hole. I was thinking about those hand pumped sprayers that the pest control guys use. I could just bend the pole that goes to the sprayer so that it could reach up into the tank and spray the coil off. What do you think? I suppose I could just fill the whole tank with a diluted solution but that would take a long time and use a whole lotta chemicals. Maybe pour in a few gallons on concentrated solution thru the hand hole. Then pump in RO water from some pre-filled trash cans to dilute. That way it gets everywhere. Seems like it would take a long time and they do NOT want lots of down time. The heaters cannot be drained separately as there are no isolation valves on the outlet manifold, only the inlet. go online and double check the manuals though.[/quote] __________________ Plumber, Repiping, Replumbing, Leak Detection, Solar Water Heater, Drain Cleaner, Pipe Leak, Polk County Plumber, Lakeland Plumber, Winter Haven Plumber, Haines City Plumber, Bartow Plumber Last edited by Protech; 08-16-2010 at 04:03 PM..

08-16-2010, 04:21 PM	#5
Protech ٩(͡๏̯͡๏)۶ Join Date: Sep 2008 Location: Polk County, Florida Posts: 7,167 My Photos	They want to sell me their proprietary "un-lime" solution which is special order and they charge a premium. Do you think it would hurt the lining if I just filled the tank with hydrochloric acid diluted with RO water 1 parts to 5 parts and then kicked the burner on until the solution was about 120F? The tanks heat to that temp in about 5 minutes. Not sure bout the cyclones, but thats what the manual used to recommend... filling the tank with diluted hydrochloric acid for those dinosaurs. It probably would do damage if you sprayed it right on the coil. Bad comparison on my part... apples oranges.[/QUOTE] __________________ Plumber, Repiping, Replumbing, Leak Detection, Solar Water Heater, Drain Cleaner, Pipe Leak, Polk County Plumber, Lakeland Plumber, Winter Haven Plumber, Haines City Plumber, Bartow Plumber

08-16-2010, 05:47 PM	#7
SewerRatz Illinois Licensed Plumber Join Date: Apr 2009 Location: Chicago Area Posts: 2,706 My Photos	The reason they want the anode rods pulled before deliming a heater is the acid used to delime the heater and the magnesium anode rod will produce large quantity of hydrogen. Unlime is the best out there, it uses phosphoric acid (same stuff in soda pop) and washes out of the heater easily and does not do any damage to the heater or pipes. The local supply here sells Unlime by the gallon for 25 bucks if I recall might be a bit more than that. It has been a while since I priced the stuff. It is cheaper to get it in the 5 gallon jug though. __________________ Ron Hasil Lic #058-160417 A-Archer Sewer & Plumbing specializing in: Tankless Water Heaters \| Drain and Sewer Cleaning Sump and Ejector Pumps \| Backflow RPZ Testing

08-16-2010, 08:53 PM	#8
Protech ٩(͡๏̯͡๏)۶ Join Date: Sep 2008 Location: Polk County, Florida Posts: 7,167 My Photos	Why not just phosphoric acid? The problem with these heaters is that they have a spiraled flame tube that is up high above the hand hole. I can scoop the scale out of the bottom but the stuff stuck to the flame tube is not easily accessible. The anodes are DC powered anodes and do not need to be removed during deliming. These heaters are only about 2 years old so they shouldn't be too bad. I think the thing to do here is sell them some isolation valves on the outlets so that each heater can be isolated and drained individually. That way I can just truck in 2 55gal drums of RO water and a few gallons of phosphoric acid. I can just mechanically remove most of the scale and then fill the heater up with the RO water/phosphoric acid mix and let it sir for a day. Come back the next day and do it all over again with the next heater. What do you think? __________________ Plumber, Repiping, Replumbing, Leak Detection, Solar Water Heater, Drain Cleaner, Pipe Leak, Polk County Plumber, Lakeland Plumber, Winter Haven Plumber, Haines City Plumber, Bartow Plumber

08-16-2010, 04:49 PM	#6
Colgar Senior Member Join Date: Jul 2009 Location: Peo, IL Posts: 1,153 My Photos	Going from memory here..... AO Smith wants the anodes pulled before deliming If you pull the access cover, have a new gasket, new bolts, drill and tap handy.....

08-16-2010, 11:07 PM	#9
Farmtek Junior Member Join Date: Feb 2010 Location: MB Canada Posts: 14 My Photos	That rydlime is a good product that works.

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