Instructions / Assembly

WHL-590 REV. 7.27.16

Figure 30 – Water Heater Installed with Combi Boiler – NOTE: There is a Built-In Flow Check in the Internal Recirculation

Pump Loop – LP-569-M

NOTE: The solenoid valve is powered by the water heater. The solenoid valve must be normally closed, energize when the water

heater is over 90% of capacity, and deactivate when water heater is less than 50% of capacity.

NOTE: When a water heater is installed with a combi boiler, ensure Installer Parameter 19:SU is set to Cd – Comfort Mode. This is the

default mode of operation. Also wire the solenoid as described in Figure 36. Failure to do so will result in improper water heater

operation.

NOTE: Ensure the DHW temperature setting is the same on the water heater and the combi boiler. Failure to do so will result in

improper water heater operation.

NOTES:

1. Minimum pipe size should match connection size. Upsize pipe accordingly if greater flow is required.

2. A thermal expansion tank suitable for potable water must be sized and installed within this piping system between the backflow

preventer and the cold water inlet.

3. All circulators should have an integral flow check.

4. Drains and check valve between water heater and piping will assist in purging air from system.

5. These drawings are meant to demonstrate system piping only. The installer is responsible for all equipment and detailing required by

local codes. In Massachusetts, you must install a vacuum relief valve per 248 CMR.

6. Mixing valve application is optional, but recommended to help prevent scalding.

7. Always shut off power to the water heater or isolate the heater from the system if ANY plumbing work is to be done. Running the

water heater without water will result in dry-firing.

NOTE: These drawings are meant to show system piping concept only. Installer is responsible for all equipment and detailing required

by local codes.