Weil-McLain SGO-W SERIES 3 OIL-FIRED NATURAL DRAFT WATER BOILER manual To pipe tankless heater

Connect Tankless Heater Piping CONTINUED

Studies have indicated that	TANKLESS HEATER RATINGS TABLE
dangerous bacteria can form in
potable water distribution system if certain minimum	BOILER		INTERMITTENT	INLET
water temperatures are not maintained. Contact local
	MODEL	HEATER	DRAW RATINGS	AND OUTLET
health department for more information.
	NUMBER	NUMBER	(GPM)*	TAPPING SIZES

To pipe tankless heater:			SGO-3W 35-S-29		3.50	¾"
1. Size piping no smaller than tankless heater
			SGO-4W 35-S-29		3.75	¾"
inlet and outlet.
2. Following controls (furnished by others) must
			SGO-5W 35-S-29		4.00	¾"
be installed:
			SGO-6W	35-S-29	4.00	¾"
a.	Automatic mixing valve. See FIGURE 14.
	(Read	at bottom of p. 16)	SGO-7W	35-S-29	4.00	¾"
			SGO-8W	35-S-29	4.00	¾"
b.	Flow regulating valve. Size according to
			SGO-9W	35-S-29	4.00	¾ "

intermittent draw of tankless heater. See

Table at right. Follow valve manufacturer’s *	Gallons of water per minute heated from 40°F to 140°F with
instructions to install.	200°F boiler water temperature. Tested in accordance with
3. Additional anti-scald devices may be installed at	I=W=H Testing and Rating Standard for Indirect Tankless Water
	Heaters Tested with Boilers.
each hot water faucet, bath and shower outlet.

4.In hard water areas, soften cold domestic supply water to heaters to prevent lime build-up.

				Tankless Heater
These single wall heat exchangers					Control
comply with National Standard
					Flow
Plumbing Code provided that:
					Regulating
•	Boiler water (including
					Valve
	additives) is practically non-
	toxic, having a toxicity rating	Cold
	or class of 1, as listed in	Water
	Clinical Toxicology of	Supply			Mixed
	Commercial Products.
•	Boiler water pressure is
	limited to max. 30 psig by
	approved water relief valve.
			12" Min.

Hot

Cold

Automatic

Mixing

Valve

Tankless Heater Piping

FIGURE 14

17