Recently the Chicagoland area has seen an unexpected increase in premature heat exchanger failures in boilers. The common cause determined by manufacturer’s inspectors has been lime/scale accumulation on the water side of the heat exchanger.
Lime/Scale accumulation in a heating boiler – A coating or layer of the dissolved minerals and solids precipitates from the water and collects on the heating surface of the boiler heat exchanger. Severe scale accumulation can partially or completely block water flow leading to thermal fatigue and heat exchanger failure. Buildup of lime/scale indicates a problem with water flow or water chemistry.
A heating boiler must operate with a closed loop system with no addition of make-up water to the boiler loop. Any system leaks must be repaired. The addition of make-up water can disrupt water quality and lead to scale formation. The chemistry of the boiler water must be maintained to prevent elevated TDS (Total Dissolved Solids) levels and scaling conditions. Proper water flow through the boiler must be maintained to carry away the heat from the boiler. Low flow can result in short cycling of operation, cycling on limit, and scale accumulation in the heat exchanger.
Failure to properly maintain the heat exchanger and the water chemistry will result in non-warrantable conditions.
DRF recommends the following steps to be taken to protect your boiler investment:
1. Annual preventative maintenance completed by manufacturers authorized service provider as described in the manufacturer’s Service Manual
2. Heating system water quality testing
3. Cleaning of both fire and water sides of the heat exchangers as a proactive measure
4. System pressure test to determine if leaks are present in the system
5. Repair of any leaks
6. Separator and filter check and clean to ensure proper water flow thru boiler
Please contact the RCS Team at DRF Water Heating Solutions if we can assist you. Call 630-615-4488 or email RCSsales@DRFtps.com.