Tag Archives: Tankless Water Heaters



HOUSTON, TX – The RectorSeal Corporation, a Houston-based manufacturer of specialty chemical products and tools for the professional trades, introduces the Calci-Free™ Tankless Water Heater Flush Kit. All the equipment needed to clean and restore efficiency to tankless water heaters.


The Calci-Free™ Tankless Water Heater Flush Kit provides the user with all the equipment necessary to pump and circulate the Calci-Free™ flushing solution through tankless water heaters to eliminate lime scale and other contaminants which can build up on the walls of heat exchanger tubes over time and block the flow of water. The kit contains a heavy duty corrosion resistant pump, an elevating strainer to separate the pump from debris, (2) seven foot hoses with swivel fittings all in a large 5 gallon pail with a threaded, sure sealing lid. The kit also contains (1) 1.2 lb. container of Calci-Free™ a dry product for safe transport that restores water flow and pressure quickly with no strong odor. One dose circulated through the unit for 20 minutes does the job. Everything needed to safely and quickly clean Tankless Water Heaters.


The Calci-Free™ Tankless Water Heater Flush Kit is now available through RectorSeal’s nationwide network of distributors or by calling Customer Service at 1-800-231-3345.

Rectorseal is celebrating 75 years of quality products. Founded in 1937, The Rectorseal Corporation is a leading manufacturer of chemical and specialty products designed for professional tradesmen. Steady growth over the years has been maintained through a commitment to providing high quality products and services.  With a diversified business strategy, RectorSeal aggressively pursues new and unique technologies to serve the plumbing, heating, air conditioning, electrical and construction industries.  The  Rectorseal Corporation is devoted to providing innovative quality products supported by strong customer and technical service.




 2601 Spenwick Drive, Houston, Texas 77055

Phone: (800) 231-3345  Fax: (713) 263-7577.

Tankless Water Heaters

tankless water heaterSo you bought a tankless water heater to save energy and money. And you thought all the problems with poor efficiency with hard water buildup was gone. But all water heaters tank or tankless develop calcium buildup during heating process. Calcium buildup is that white deposits that accumulate on showers and on faucets. This also builds up inside the water heater. The harder your water the more buildup. When water is heated the calcium particles are released and either go through the plumbing system or remain in the tankless heat exchanger and overtime these deposits accumulate and coat the heat exchanger decreasing the efficiently of the heater. When the heater becomes less efficient your money savings are gone. What about water softeners, this can reduce the buildup but can cause rusting and corrosion.

So what do you do? Clean and clean often. All tankless water heater manufacturers recommend cleaning at least once per year, in hard water areas, clean twice a year.

How do you clean a tankless water heater?

1. Shut off water supply to the water heater from the inlet and outlet valves and relieve pressure.

2. Disconnect the water heater at the energy source. Disconnect inlet and outlet water valves.

3. Use a recirculation pump to feed the cleaning solution into the water heater. Recirculate for 20 minutes or until the unit is clean. Clean inside of the heat exchanger only.

4. After cleaning, dispose used cleaning chemicals in accordance with local regulations.

5. With the energy source turned off, flush the water heater thoroughly for 10 minutes with cold water.

6. Reconnect the inlet and outlet water valves and turn water back on. Reconnect the water heater to the energy source.

What do you use?

Vinegar or RectorSeal® recommends Calci-Free™ Tankless Water Heater Flush for maximum cleaning.  For more information on this product visit RectorSeal.com.