Part number 550-100-305/0916
90
AquaBalance
TM
W
ALL
M
OUNT
GAS
-
FIRED
WATER
BOILER
— C
OMBI
Boiler Manual
33
Maintenance
(continued)
Before you start check the compatibility of chemi-
cal cleaning product with the material of the heat
exchanger. The material of domestic hot water
circuit is stainless steel, class AISI 316.
Actions for chemical cleaning of
Domestic hot water circuit
1. Disconnect the unit from the electrical power supply using
the switch and/or the special cut-off devices.
2. Close the valve of cold water inlet placed before the boiler
inlet.
3. Release residual pressure in domestic hot water circuit in the
boiler by opening a hot water tap downstream of the boiler.
4. Disconnect the piping from 1/2” cold water inlet (4) and
domestic hot water outlet (2).
5. Connect the two hoses of the pump for chemical cleaning to
the 1/2” cold water inlet (4) and domestic hot water outlet
(2).
6. Fill the pump tank with the de-scaling chemical that is NSF
approved.
7. Circulate the fluid within the domestic hot water circuit by
activating the pump switch.
8. The processing time must be chosen according to the amount
of scale deposits present in the heat exchanger and however
such time must always be less than the maximum treatment
time specified by the manufacturer on the product data sheet.
9. At the end of the cleaning cycle, empty the pump from
chemical and recover the product in appropriate containers
for disposal.
10. Fill the pump with water and perform a washing cycle in
order to remove the chemical product still present within the
coils of the heat exchanger, recovering the liquid in suitable
containers for disposal.
11. Repeat the washing with water more than once if necessary.
12. Disconnect the two hoses of the pump for chemical cleaning
from the 1/2” cold water inlet (4) and domestic hot water
outlet (2).
13. Reconnect the piping to 1/2” cold water inlet (4) and
domestic hot water outlet (2).
14. Open the valve of cold water inlet placed before the boiler
inlet.
15. Reconnect the unit to the electrical power supply using the
switch and/or the special cut-off devices and turn it ON.
16. Check the correct operation of the boiler and functionality
of production of domestic hot water.
Hot Water Can Scald!
s
Consumer Product Safety Commission and some
states recommend domestic hot water temperature of
130°F or less.
s
When installing an automatic mixing valve, selection
and installation must comply with valve manufac-
turer’s recommendations and instructions.
s
Water heated to a temperature suitable for clothes
washing, dish washing and other sanitizing needs will
scald and cause injury.
s
Children, elderly, infirm, or physically handicapped
persons are more likely to be injured by hot water.
Never leave them unattended in or near a bathtub,
shower or sink. Never allow small children to use a hot
water faucet or draw their own bath. If anyone using
hot water in the building fits this description, or if
state laws or local codes require certain water tempera-
tures at hot water faucets, take special precautions:
s
Install automatic mixing valve set according to those
standards. (If used).
s
Use lowest practical temperature setting.
s
Check water temperature immediately after first heat-
ing cycle and after any adjustment.
Studies have indicated that dangerous bac-
teria can form in potable water distribu-
tion systems if certain minimum water tem-
peratures are not maintained. Contact local
health department for more information.
These single wall heat exchangers comply with National
Standard Plumbing Code, provided that:
s
Boiler water (including additives) is practically non-
toxic, having a toxicity rating or class of 1, as listed in
Clinical Toxicology of Commercial Products.
s
Boiler water pressure is limited to max. 30 psig by
approved water relief valve.
Actions for disassembling of the
Domestic hot water flat plate heat
exchanger
Consider removing side panels as noted on page 99.
1. Disconnect the unit from the electrical power supply using
the switch and/or the special cut-off devices.
2. Close the valve of cold water inlet placed before the boiler
inlet.
3. Release residual pressure in domestic hot water circuit in the
boiler by opening a hot water tap downstream of the boiler.
Wait until heat exchanger/boiler is cooled down
before proceeding. Water in brazed plate heat
exchanger may still be
HOT
!
Failure to do so can cause severe injury.
