Horizontal 3” Boiler Instructions v1.2
Copyright - Chiltern Model Steam Engines
Page 8.
Turn off the gas to the burner immediately if it is suspected the boiler is running low or if steam
stops coming from the boiler.
Boiler Water Level Gauge (optional)
The optional water level gauge if fitted will provide a visual indication of the amount of water in the
boiler.
If bubbles get trapped in the water gauge’s glass tube making it difficult to get an accurate reading,
use the draw down valve on the base of the water gauge to vent a little air/steam. Take precautions
as this will be scolding hot.
The water gauge has a replaceable 5mm glass tube which can be accessed by removing the blanking
nut on top of the gauge. Replacement tubes are available from multiple model engineering
suppliers. Only finger tighten the tube retaining nuts.
Gas Regulator/Valve and Pipe
The connection of the gas supply should be checked before every use.
If the optional Chiltern Model Steam Gas Canister Regulator and Pipe is not being used, ensure that
there is a valve connected directly to the gas canister or tank which can be used to turn off the gas
supply. The gas regulator/valve should also be capable of graduated control of the supply to the gas
burner once the boiler is up to steam.
The supply pipe from the canister/tank must be connected securely to the burner’s gas jet carrier,
use PTFE tape to get a good seal on the threads. Check this if the optional regulator/pipe adapter is
purchased from Chiltern Model Steam. Also check the connection of the regulator to the
canister/tank is secure.
Gas Canister/Tank
For safety reasons ensure the gas canister or tank is located away from the burner in a secure
location.
After extended use the pipe, gas canister or tank’s surface can, in exceptional circumstances,
become cold enough to stick to your skin, so use gloves.
If a gas tank is used please follow the supplier’s installation and operational instructions especially
for filling.
Positioning of the canister/tank is very important for both safety and good operation.
Propane/Butane gas is stored as a liquid, but changes to a gas as it mixes with air. As gas from the
top of the canister/tank is drawn off, more of the liquid below it turns to gas and this process causes
a drop in temperature which also lowers the pressure within the canister/tank. If allowed to get too
cold, then the pressure of gas can drop until it is insufficient to maintain steam production.
To offset this temperature drop, turn off the gas and let the canister/tank warm up naturally. It is
also possible to make use of the conducted and radiated heat from the boiler to maintain a good