HTP MODCON1000 - Page 20

LP-428 Rev. 6.6.16
20
Figure 6 - Cascaded Space Heating - Indirect Priority on One
The piping will not support the weight of the circulators. Refer to the circulator manufacturer’s instructions to properly support
the circulator. Failure to comply with these instructions could result in property damage, severe personal injury, or death.
An ASSE 1017 thermostatic mixing valve is recommended on all tanks if the hot water temperature leaving the tank is above
119
o
F. Failure to do so could result in substantial property damage, serious injury, or death.
FIGURE NOTES:
1. This drawing is meant to demonstrate system piping concept only.
2. A mixing valve is recommended if the DHW temperature is set above the factory setting of 119
o
F.
3. Install a minimum of 12 diameters of straight pipe upstream of all circulators.
4. Install a minimum of 6 diameters of straight pipe up and downstream of all closely spaced tees.
5. Piping shown is Primary/Secondary.
6. The minimum pipe size for connecting an HTP indirect red water heater is 1”.
7. The minimum pipe size for connecting a Mod Con boiler is 3” for both the 1000 and 1700 models. See Multiple Boiler Manifold Piping chart,
this manual, when sizing and installing a multiple boiler system.
8. System ow (Secondary Loop) must be greater than the boiler’s Primary Loop ow.
9. Installations must comply with all local codes.
10. In Massachusetts, a vacuum relief valve must be installed on the cold water line per 248 CMR.
11. System sensor must be placed as shown in the drawing.