Steffes 5140 Owner & Installers Manual - Manual (Page 20)

PluMBinG
The Comfort Plus Hydronic heating system MUST be plumbed with a primary loop and secondary (zone)
loops. The primary loop needs to consist of a minimum of 10' of 1" pipe and requires its own pump (circulator).
The secondary (zone) loops require additional pump(s) to operate effectively. Refer to Typical Primary Loop
(Figure 16) and the Typical System Plumbing Diagrams (Figures 17 and 18) for installation information.
The primary loop serves to regulate heat transfer from the system’s heat exchanger. The primary loop pump must
be powered by the Comfort Plus Hydronic control system as shown in Figure 17-18.
Step 1 Remove the exchanger access
panel and locate the pressure
relief valve assembly.
Step 2 Connect the pressure relief
valve to the outlet water port
on the left side of the Comfort
Plus Hydronic. It is extremely
important that the following conditions for installation
of this part are met:
• Ensure all connections, including the valve inlet
are clean and free from any foreign material.
• Use pipe compound sparingly, or tape on external
threads only.
• Mount the pressure relief valve in a vertical, up-
right, position directly to the outlet water port of
the system. Under no circumstances should there
be a flow restriction or valve of any type between
the safety relief valve and the pressure vessel.
Step 3 Use schedule 40 pipe to install a discharge line for the pressure relief valve. This discharge line MUST:
• be connected from the valve outlet with no intervening valve and directed downward to a safe point
of discharge.
• allow complete drainage of both the valve and the discharge line.
• be independently supported and securely anchored to avoid applied stress on the valve.
• be as short and straight as possible.
• terminate freely to atmosphere where any discharge is clearly visible and is at no risk of freezing.
• terminate with a plain end that is not threaded.
• be constructed of a material suitable for exposure to temperatures of 375 o F or greater.
PreSSure relief valve inStallation
Risk of discharged hot water and/or
steam. Can cause personal injury or
property damage. During operation,
the pressure relief valve may discharge
large amounts of steam and/or hot
water. To reduce the potential for bodily
injury or property damage, install a dis-
charge line.
CAUTION
Installation  3.11 Comfort Plus Hydronic Comfort Plus Hydronic Installation  3.12
WARNING
Risk of explosion. Can cause injury or death. The factory supplied
pressure relief valve MUST be connected to the system with the
supplied fittings.
 DO NOT modify this assembly.
 DO NOT cap, plug, or otherwise obstruct the outlet of the
pressure relief valve.
 DO mount the pressure relief valve in a vertical, upright position.
 This pressure relief valve is sized to service the needs of the
Comfort Plus Hydronic heating system. If multiple heating
systems are being used, pressure relief valving for the other system MUST be provided
separately.
Available Pressure
relief Valves
Minimum
BTU rating
Maximum
Operating Pressure
Order
Item #
30 PSI 400,000 20 PSI 1100104
75 PSI 500,000 60 PSI 1100105
Note: 5100 Series Systems are shipped with 30 pSI pressure relief valves.
If a different valve is required order the item number listed above.