Frequently Asked Questions — Lochinvar Parts & Equipment
Common questions from contractors, facilities managers, and service technicians about Lochinvar replacement parts and complete units. Contact us or call (901) 458-2000 — we'll help identify the correct OEM part for your model and serial number.
How do I find the right Lochinvar replacement part for my unit?
You need both the model number and serial number from the rating plate on your Lochinvar unit. The serial number is critical because Lochinvar has updated parts mid-production run — the same model can use different igniters, sensors, or control boards depending on manufacture date. Call (901) 458-2000 with both numbers and we'll identify the correct OEM part number.
What is the most commonly replaced part on a Lochinvar Knight boiler?
The most frequently replaced parts are hot surface igniters, flame sensors (flame rods), temperature sensors (inlet/outlet), pressure switches, and gas valves. Flame sensor degradation is the leading cause of intermittent lockouts — carbon buildup on the sensor prevents it from reading the flame signal. Igniters crack from thermal cycling. Pressure switches fail from blocked condensate traps or deteriorated diaphragms.
What is the difference between the Lochinvar Knight WHB and KHB?
The WHB is the wall-mount version of the current-generation Lochinvar Knight fire tube boiler; the KHB is the floor-mount version. Both use the same fire-tube stainless steel heat exchanger and SMART SYSTEM control, and both achieve 95% AFUE in models from 55,000 to 399,000 BTU/hr input. The WHB includes an ECM variable-speed pump as standard. The KHB is free-standing and better suited when wall mounting is not practical.
What replaced the Lochinvar Knight WBN water tube boiler?
The WBN series (water tube, wall-mount) was replaced by the WHN and then the current WHB series (fire tube, wall-mount). The KBN series (water tube, floor-mount) was replaced by the current KHB series. The current-generation Knight uses a fire-tube stainless steel heat exchanger rather than the earlier water tube design. OEM replacement parts for WBN and KBN units are still available through Memphis Control Center.
What is the difference between the Lochinvar Crest and Knight?
The Knight (55,000–399,000 BTU/hr) is designed for residential and light commercial hydronic heating. The Crest (750,000–6,000,000 BTU/hr) is a commercial condensing fire tube boiler for hospitals, universities, hotels, and large commercial buildings. The Crest uses Lochinvar's proprietary wave fire-tube heat exchanger, SMART TOUCH control with CON·X·US remote monitoring, up to 96.2% efficiency, and up to 20:1 turndown ratio.
What is the difference between the Lochinvar ARMOR and Copper-Fin commercial water heaters?
The ARMOR (AWN/AWH) is a condensing commercial water heater with a stainless steel heat exchanger — up to 99% thermal efficiency through flue gas heat recovery, requiring direct vent installation. The Copper-Fin (CWN/CFN) is an atmospheric or direct-vent non-condensing water heater with copper finned-tube heat exchanger — simpler design, lower first cost, typically 80–85% efficiency. ARMOR is best when operating cost savings are the priority; Copper-Fin when first cost, simplicity, or venting constraints favor a non-condensing design.
Does Memphis Control Center sell complete Lochinvar units, not just parts?
Yes. While OEM replacement parts are our primary Lochinvar business, we can source complete Lochinvar units — Knight boilers, Crest commercial boilers, ARMOR water heaters, Copper-Fin water heaters, EnergyRite pool heaters, and more. Call (901) 458-2000 for availability, pricing, and lead time. As a CGNA Elite Distributor, we access a national network of inventory beyond what is listed on our site.
What does SMART SYSTEM mean on a Lochinvar boiler?
SMART SYSTEM is Lochinvar's proprietary integrated operating control on Knight boilers — LCD display, control of up to three temperature setpoints, outdoor reset, night setback, freeze protection, modulating burner control, and diagnostic fault codes. SMART TOUCH is the commercial version on Crest boilers and ARMOR water heaters, adding CON·X·US remote monitoring via Ethernet or cellular and Modbus/BACnet communication for building automation integration.
Who manufactures Lochinvar and where?
Lochinvar, LLC was founded in 1939 and acquired by A.O. Smith Corporation (NYSE: AOS) in August 2011 for $418 million. Lochinvar operates as a wholly owned A.O. Smith subsidiary, headquartered and manufactured at 300 Maddox-Simpson Parkway, Lebanon, Tennessee in a 360,000 sq. ft. facility. A.O. Smith is one of the world's largest water heater manufacturers. Lochinvar specializes in high-efficiency boilers, commercial water heaters, heat pumps, pool and spa heaters, and storage tanks — sold exclusively through the professional plumbing and heating contractor channel.
