Crown Boiler BIMINI BWC225, Installation Instructions Manual

Page: 41 / 73

WATER QUALITY AND BOILER WATER ADDITIVES
IMPORTANT NOTE
This boiler is equipped with an aluminum heat exchanger that can be seriously damaged by failure to
follow the following guidelines:
1) Flush the system before connecting the boiler - In a replacement installation, flushing the system will
remove sediment, solder flux, and traces of old boiler additives. Even if the system is new, do not omit this
step - new systems will contain solder flux and may even contain sediment.
2) Make sure that the system is tight - This is the single most important guideline . Tap water contains
dissolved oxygen which causes corrosion. In a tight system, this oxygen comes out of solution and is
quickly removed from the system through the automatic air vent. The system then remains essentially free
of oxygen. If the system is not tight, however, frequent additions of make-up water can expose the heat
exchanger to oxygen on a continuous basis. In addition, frequent additions of hard make-up water can
cause calcium deposits to collect in the heat exchanger, causing severe damage.
To minimize additions of make-up water:
• Inspect the system thoroughly for leaks before placing it in service.
• If the system includes underground piping, or other piping in which a leak might go undetected,
consider isolating the boiler from the system with a heat exchanger. Alternatively, consider
installing a water meter in the fill line to record additions of make-up water.
• Make sure that the expansion tank is properly sized and in good condition. If it is not, the relief
valve may open frequently, resulting in regular additions of make-up water.
3) Radiant Tubing and Oxygen Barriers - Even if the system is tight, oxygen can be introduced into the
system through some types of non-metallic tubing used in radiant or snow melt systems. Other non-
metallic tubing is equipped with an oxygen barrier to prevent migration of oxygen into the water. If the
boiler is to be installed in a system containing non-metallic tubing without an oxygen barrier, it must be
isolated from the boiler with a heat exchanger as shown in Figure 9.10.
4) Antifreeze - Do not use antifreeze unless absolutely necessary. If antifreeze must be used, the only
permitted antrifreezes are:
• Fernox Alphi-11
• Fernox CHP in USP Grade virgin propylene glycol (available from Crown)
• RhoGard Aluminum Safe Multi-Metal Antifreeze
If either of the above antifreezes are used, test the boiler water on an annual basis to ensure that the
antifreeze remains non-corrosive. This is done with Fernox test kit I-TK (available from Crown).
5) Other Antifreezes and Boiler Additives - Do not add other additives unless they are specifically
approved in writing by Crown for use with this boiler. This includes other “aluminum safe” antifreezes.
6) System PH - Maintain the PH in the system between 6.5 and 8.5.
39