AA130 Domestic Hot Water Coil Clogged???

hello all ,my aa130 has been running for 4 yrs now, its great ,, but my hot water has no pressure at the tap, cold water has good pressure and volume. now I think my hot water coil may be clogged??? we have a well here, the water coil came with the boiler and it flowed when I put the boiler in , so do you think this is my problem and how do you clean the coil .also can you do it while the boiler is in operation??? any help /advice will be greatly apprecieated, I don't know how old the water coil is ,the boiler is from the early 50s, thank you tommy

There are some acids available to descale the coil, some are safe and some are real nasty so do your homework if you attempt it yourself. A pro should be able to do it in a short time, probably a lot cheaper than a new coil.

What's the hardness of your water? Do you treat your well water before it goes into the coil?

Copper coil I would assume ... and copper will dissolve in strong acids [HCl, H2SO4, H3PO4] (the same acids that dissolve the salts that are likely clogging the coil - so clear the salts and also dissolve the copper---when using and acids to clean).

Can you take the coil out?

I would get some CLR (it contains some acid but not acid that is the type that is harmful to the copper) and hook the coil up to a gallon of the CLR and start circulating the CLR through the coil via a small pump (or worse come to worse, gravity feed it). I would adjust the CLR to a low viscosity fluid if it is not already via water/alcohol addition (rubbing alcohol can be source of [OH]).

If you want to talk .. shoot me a PM w/your phone # ...

Are you sure it's clogged in the coil? Did you try different taps?

davidmcbeth3 wrote: Copper coil I would assume ... and copper will dissolve in strong acids [HCl, H2SO4, H3PO4] (the same acids that dissolve the salts that are likely clogging the coil - so clear the salts and also dissolve the copper---when using and acids to clean).

Yes, the acids will eat the copper but it would need a long time to do it, not the case with the salts that are clogging it. If it eats the coil in an hour, it needed to go anyway.

I used citric acid to clean the ultrafilter on the wastewater system I used to run. It would clean the salts and metals from the membrane very quickly. Usually it would clean up in under an hour. It took 20 years but it finally started pin holing the carbon steel here, there and everywhere.

thank you for replying .now can this coil be cleaned with the boiler in operation,,hot, ????or do I have to shut her down

Yes, the heat actually helps. You just need to get into the coil. If there are no unions, simply cut the copper tubing with a tube cutter and you can re install with unions. You will probably need to remove the tubing adapters at the coil so pay attention that the cuts allow you to remove them. Once they are removed, you can install what you need to descale. Probably a couple elbows and nipples should do it. Just be careful and read the directions for the product you use. Citric acid is found in candy and pharmaceuticals so it is very safe. There are some nasty compounds at the other end of the spectrum.

you cut the in and out lines and install a shut off with a boiler drain right next to it on each pipe, with the boilerdrain toward the coil on both. you can now pump your acid of choice INTO to the outgoing pipe and drain into a bucket on the supply side. Note both shutoffs are off. I use muriatic acid (about 1 qt to 3 gals of water) if that makes you nervous use cider vinegar its just a little slow. circulate the solution through the coil slowly adding more acid untill you stop getting big bubbles coming out the hose back into the bucket. When that happens empty the pail , disconnect the pump put the hose in the bucket . Remove supply hose and close that BD leaving the other one open . slowly open the shutoff on the supply side and fill pail a few times to flush all the acid any crap out. close BD open downstream shutoff and hit the shower. Now you can periodically clean your coil in about ten minutes . That is all....

Do you have a mixing valve in the system?