Laclede gas customer rebates

Get great financing by paying off your new energy efficient water heater or gas furnace through your monthly gas bill.
Laclede will give you rebates and help install the new appliances.

Rebates for home and commercial customers using natural gas by Ameren

Ameren has funds for anyone who wants to reduce their gas utilities by obtaining energy efficient furnaces, water heaters or thermostats.
Please see the link for more details.
You have to be an Ameren Natural Gas customer though.