A.O. Smith VB 1500 User Manual - Operation
10
OPERATION
IMPORTANT
Only a Certified Start-up agent should perform the initial
firing of the boiler. At this time the user should not hesitate
to ask the start-up technician any questions regarding the
operation and maintenance of the unit. If you still have
questions, please contact the factory or your local A.O.
Smith representative.
Lighting and Operating instructions are included with this manual.
By using these instructions, the user may be able to make minor
operational adjustments and save unnecessary service calls.
However the user should not attempt repairs, but should
contact a service technician or gas supplier.
GENERAL
Never operate the boiler without first making sure the boiler
andsystemarefilledwithwater,inaddition:
Forhotwatersupplyinstallations:
• Make sure the pressure relief valve is installed at the
boiler and a temperature/pressure relief valve installed
in the storage tank. Also check for leaks.
Forheatingboilerinstallations:
• Makesurethattheboilerandsystemhavebeenpurgedofair
and checked for leaks.
Also be sure to check the gas piping for leaks before beginning the
initialfiringoftheboiler.
FILLING AND PURGING OF HEATING
BOILER INSTALLATION
1. Fast fill system through bypass until pressure approaches
desired system pressure. Close bypass valve and permit
pressure to be established by the pressure reducing
valve.
2. Vent all high points in system to purge system of air.
Provisions should be made to permit manual venting of radiators
or convectors.
FILLING HOT WATER SUPPLY
BOILER INSTALLATION
1. Close the system’s drain valve by turning handle clockwise.
2. Open a nearby hot water faucet to permit the air to escape.
3. Fully open the cold water inlet pipe valve allowing the boiler
andpipingtobefilled.
4. Closethehotwaterfaucetaswaterstartstoflow.
5. The boiler is ready to be operated.
PURGING GAS LINE
Gas line purging is required with new piping or systems in which
air has entered.
INLET GAS PRESSURE
The inlet gas pressure is measured by removing the 1/8” NPT Plug
located on the upstream side of the supply gas valve, and insert
a1/8”NPThosebarbfittingtobeconnectedtoamanometeror
pressure gauge. Once pressure has been checked and/or adjusted,
replacetheplugandcheckforleaks.Themaximumvaluespecified
on the rating plate must not be exceeded. The minimum values,
shown on the rating plate, must be maintained under both load and
noloadconditions(staticandfiringconditions).Thecombination
gas valves supplied with the boiler are for low pressure service.
If upstream pressure exceeds 14.0” W.C., an intermediate gas
pressure regulator of the lockup type must be installed.
Gas Valve
Manual Gas
Shutoff Valve
(up stream)
Manual
Shutoff Valve
(down stream)
Venturi
Blower
Condensate
Pan
Adapter
FIGURE 3. GAS TRAIN ASSEMBLY.