Table of Contents
Advertisement
The boiler cannot be drained completely of water without
purging the unit with an air pressure of 15 PSI.
10. The relief valve and temperature and pressure gauge
are included in the accessory kit. A discharge line should be
installed 6" above the drain in the event of a pressure relief.
The pipe size must be the same size as the relief valve outlet.
NEVER BLOCK THE OUTLET OF THE SAFETY RELIEF
VALVE.
J. Fill and Purge Heating System
1. Attach the hose to balance and purge hose connector or
drain valve and run hose to nearest drain.
2. Close the other side of the balance and purge valve or shut
off valve after the drain.
3. Open the first zone balance and purge or drain valve to let
water flow out of the hose. If zone valves are used, open the
valves one at a time manually. NOTE: You should check zone
valve manufacturer's instructions prior to opening valves
manually, so as not to damage the zone valve.
4. Manually operate fill valve regulator. When water runs out
of the hose, you will see a steady stream without bubbles.
Close the balance and purge valve or drain to stop the water
from flowing. Disconnect the hose and connect it to next zone
to be purged.
5. Repeat this procedure for additional zones (one at a time).
For installations that incorporate standing iron radiation and
systems with manual vents at the high points, follow the
previous section and, starting with the nearest manual air
vent, open the vent until water flows out. Then close the vent.
Repeat the procedure, working your way toward the furthest
air vent. It may be necessary to install a basket strainer in
an older system where larger amounts of sediment may be
present. Annual cleaning of the strainer may be necessary.
Upon completion, make sure that the fill valve and zone valves
are in automatic positions. You must also assure the purge and
shut off valves are in open positions.
K. Glycol Antifreeze Solutions
Use only inhibited propylene glycol solutions which are
specially formulated for hydronic systems. Ethylene glycol
is toxic and can attack gaskets and seals used in hydronic
systems. Glycol mixtures should not exceed 50%. Failure to
do so could result in property damage, severe personal injury,
or death due to scalds.
•
Glycol in hydronic applications should include inhibitors
that prevent the glycol from attacking metallic system
components. Make certain that the system fluid is
checked for the correct glycol concentration and inhibitor
level.
•
The glycol solution should be tested at least once a year
or as recommended by the glycol manufacturer.
•
Anti-freeze solutions expand more than water. For
example: A 50% by volume solution expands 4.8% in
volume for a temperature increase from 32
while water expands 3% over the same temperature rise.
Allowances must be made in system design for expansion.
•
A 30% mixture of glycol will result in a BTU output loss of
15% with a 5% increase in head against the system circulator.
•
A 50% mixture of glycol will result in a BTU output loss
of 30% with a 50% increase in head against the system
circulator.
It is highly recommended that you carefully follow the glycol
manufacturer's recommended concentrations, expansion
requirements, and maintenance recommendations (pH additive
breakdown, inhibitor reduction, etc.) You must carefully
calculate the additional friction loss in the system as well as the
reduction in heat transfer coefficients.
L. Zoning with Zone Valves
1. When zoning with zone valves, connect the boiler to the
system as shown in Applications. The primary/secondary piping
shown ensures the boiler loop will have sufficient flow. It also
avoids applying the high head of the boiler circulator to the zone
valves.
2. Connect DHW (domestic hot water) piping to indirect storage
water heater as shown in Applications.
M. Zoning with Circulators
1. When using circulator zoning, connect the boiler to the system
as shown in Applications. NOTE: The boiler circulator cannot be
used for a zone. It must only supply the boiler loop.
2. Install a separate circulator for each zone.
3. Connect DHW (domestic hot water) piping to indirect storage
water heater as shown in Applications.
N. Multiple Boilers
1. Connect multiple boilers as shown in Applications.
2. All piping shown is reverse return to assure balanced flow
throughout the connected boilers.
3. Each connected boiler must have its own circulator pump to
assure adequate flow.
4. Connect DHW (domestic hot water) piping to indirect storage
water heater as shown in Applications.
5. The system flow (secondary loop) must be greater than the
boiler's primary loop flow.
o
o
F to 180
F,
19
WHL-016 Rev. 4.14.16
Advertisement
Table of Contents
