NTI INSTALLATION MANUALS

Part 4 - Water Piping

B. Back ow Preventer Use a back ow preventer speci cally designed for hydronic boiler installations. This valve should be installed on the cold water ll supply line per local codes.

WARNING

A. General Plumbing Information The water connections must be installed in accordance with all local and national plumbing codes, or any applicable standard which prevails. • Pipe material must be suitable to meet local codes and industry standards. • The pipe must be cleaned and without blemish before any connections are made. • The size of the DHW pipes should be 3/4” diameter, and the CH pipes should be 1” diameter. • Isolation (shut-o valves) should be used on both the CH and DHW loops to ease future servicing. • All piping should be insulated. • If the Combi Boiler is installed with a back ow preventer in the DHW cold water supply line, means shall be provided to control thermal expansion. Contact the water supplier or a local plumbing inspector on how to control this situation. It is recommended to install a sweat shut-o valve and a union in the return and supply piping to ease future servicing. If there is a back ow preventer or any type of a no return valve in the system, install an additional tee here suitable for an expansion tank. NOTE: The addition of a high temperature limiting device is important if the boiler is to be connected to a domestic hot water system. The boiler control module uses temperature sensors to provide both high limit protection and modulating temperature control. The control module may also provide low water protection by sensing the water level in the heat exchanger. Some codes/jurisdictions may require additional external controls. The building piping system must meet or exceed the piping requirements in this manual. Use two wrenches when tightening water piping at boiler. Use one wrench to prevent the boiler return or supply line from turning. Failure to prevent piping connections from turning could cause damage to boiler components. Plumbing of this product should only be done by a quali ed, licensed plumber in accordance with all local plumbing codes. The boiler may be connected to an indirect water heater to supply domestic hot water. NTI o ers indirect water heaters in a wide range of gallon sizes in stainless steel construction. Dielectric unions or galvanized steel ttings must not be used in a system with this boiler. Doing so WILL VOID the warranty. Use only copper, brass, black iron, or stainless steel ttings. Do not apply a torch within 12” of the boiler. If sweat connections are used, sweat tubing to the adapter before tting adapter to the water connections on the boiler. Damages due to improper installation practices ARE NOT covered by warranty. Failure to follow the instructions in this section WILL VOID the warranty and may result in property damage, severe personal injury, or death. The National Standard Plumbing Code, the National Plumbing Code of Canada, and the Uniform Plumbing Code limit heat transfer uid pressure to less than the minimum working pressure of the potable water system up to 30 PSI maximum. In addition, the heat transfer uid must be water or another non-toxic uid having a toxicity of Class 1, as listed in Clinical Toxicology of Commercial Products, 5th Edition. Failure to follow this warning could result in property damage, severe personal injury, or death. CAUTION CAUTION

C. Expansion Tank

Expansion Tank and Make-Up Water 1. Ensure that the expansion tank is designed and sized to correctly handle boiler and system water volume and temperature.

WARNING

Expansion tanks must be sized according to total system volume. This includes all length of pipe, all xtures, boilers, etc. Failure to properly size for system expansion could result in wasted time, money, possible property damage, serious personal injury, or death.

CAUTION

Undersized expansion tanks cause system water to be lost from the relief valve, causing make-up water to be added. Eventual boiler failure can result due to excessive make-up water addition. SUCH FAILURE IS NOT COVERED BY WARRANTY. DO NOT install automatic air vents on closed type expansion tank systems. Air must remain in the system and return to the tank to provide an air cushion. An automatic air vent would cause air to leave the system, resulting in improper operation of the expansion tank.

Model

Heat Exchanger Volume (Gallons)

TRX085

1.1

TRX120

1.2

TRX110C

1.1

2. The expansion tank must be located as shown in Applications, this manual, or following recognized design methods. See expansion tank manufacturer’s instructions for details. 3. Connect the expansion tank to the air separator only if the air separator is on the suction side of the circulator. Always install the system ll connection at the same point as the expansion tank connection to the system. 4. Most chilled water systems are piped using a closed type expansion tank. DIAPHRAGM (OR BLADDER) EXPANSION TANK Always install an automatic air vent on top of the air separator to remove residual air from the system. 1.2 Table 10 - Heat Exchanger Water Volume (To Aid in Expansion Tank Sizing) TRX150C NOTE: Observe the minimum 1” clearance around all uninsulated hot water pipes when openings around pipes are not protected by non combustible materials. Use at least the MINIMUM pipe size for all appliance loop piping. This is to avoid the possibility of inadequate ow through the appliance. Using less than the required minimum pipe size and piping could result in system problems, property damage, and premature appliance failure. Such problems ARE NOT covered by product warranty. Boiler Models should not be operated as a direct potable hot water heater. Only Combi Models should be used to directly heat hot water. CAUTION D. Piping the Boiler

25