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42
Tank Cleaning
As the water in the steam generator boils away, the minerals in that water come out of suspension and are deposited on the
walls of the tank and on the electrodes. This process leaves the tank walls coated with a white or light brown colored mineral
buildup. This buildup may be anywhere from soft and chalky to rock hard. The automatic drain cycle will minimize mineral
buildup but, eventually, the tank will need cleaning.
Tank cleaning is indicated when:
a. The unit has been in service for a period of time, a solids buildup is visible through the tank walls, and the “normal”
water level in the tank is rising, or;
b. The display indicates a maintenance message
Steam cylinder cleaning
This procedure is intended as a guide only for the chemical cleaning of the generator in all EHU models. Read and follow
label directions on any cleaning product. Check local codes before disposing of chemicals.
Caution: Read and follow carefully the safety procedures on the package
1. Obtain Armstrong Rite-Qwik or similar non-hydrochloric/muriatic acid cleaning solution.
2. Remove the tank, following the “Tank Removal” directions in this manual.
3. Let the steam generator tank cool after removal from the EHU unit.
4. Split the tank and examine the inside of the tank and the electrodes.
a. If the tank is black or dark brown, the electrodes may have disintegrated and chemical cleaning may not be effective.
The tank can be cleaned with the following process, but the electrodes, may need to be replaced.
b. If tank and electrodes have a white/tan/grey mineral accumulations and/or the tank is partially filled with loose lime
accumulations, proceed with chemical cleaning.
5. Empty any loose deposits from the bottom tank half. Both tank halves and the barrier assembly, if present, can be
cleaned using a scraper, a stiff bristle brush, and water spray as required.
6. Remove the electrodes from the upper tank half, following the directions on page 50 of this manual. Loose and/or soft
deposits should be scraped from the exterior of the electrodes before chemical cleaning.
7. Prepare the chemical cleaning solution as per manufacturer’s recommendations and fill a plastic bucket to a sufficient
level to soak the electrodes. Be certain not to submerge the electrodes beyond the level of the screen.
8. Let the cleaning action take place for 15 minutes. Remove the electrodes from the bucket and rinse them thoroughly
with a clean water spray.
9. Observe the electrodes to determine if another treatment is necessary.
10. It is not necessary for the electrodes to be cleaned down to bare metal. Removal of major accumulations is the only
requirement.
11. Helpful Hints:
Check the drain valve for proper operation & good flow when the tank is drained prior to removal.
* With the tank removed, inspect the drain adaptor and hose from adaptor to drain valve to ensure that it is free from
deposits which may interfere with proper drainage.
12. Reassemble tank. Make sure o-rings are still on electrode terminals. Also check condition of steam generator o-ring. Af-
ter a couple cleanings, it will need to be replaced. Make sure o-ring is sealed in its groove and not pinched when halves
are put together. Do not over-tighten nuts that hold electrodes in place. This is an o-ring seal so nuts should be “snug”.
13. Re-install the steam generator tank. Check out for proper operation.
