You would consider it the height of insanity to send an untrained, ill-prepared service technician out on a call without any tools. The only thing crazier would be expecting him to solve the customer's problem. Yet, service companies do it all the time. They don't send the technician out ill-prepared technically, just ill-prepared to answer customer questions about new services and products.
Technicians aren't salespeople. They aren't inclined to be salespeople. That's why they're technicians. They like to work with their hands. Yet, they're also the primary point of customer contact for your company. They're presented with sales opportunities every day that they simply let slip through the cracks because they don't recognize them and don't know how to handle them.
You won't make salespeople out of your technicians. You'll probably lose them to the competition if you try. But, you can expect them to hand the customer basic information about products and services that might be of interest. And you can expect them to answer questions, honestly, that the homeowner asks after reading the information.
Don't try to make your technicians razzle dazzle promoters. But do give them simple, basic brochures they can give to the homeowner to look at while they're performing their diagnostic or the repair.
For example, a technician that's on a water heater call might give the homeowner a brochure explaining the benefits of quick recovery water heaters. The brochure might suggest that quick recovery is effectively the same as a larger water heater without taking up more space (i.e., more hot water). It could explain that quick recovery allows the homeowner to get the same amount of hot water with a smaller tank, saving energy through reduced standby losses. It's not rocket science. But it's something most technicians are ill-equipped to explain. Let the printed material explain it for them. It will prompt the homeowner to ask questions, which the technician can then answer.
How would a quick recovery brochure help? First, a homeowner might conclude that they're tired of their old water heater and opt for a new quick recovery unit even if the existing water heater is repairable (e.g., a gas valve, thermocouple, element, or burner failure). If the existing water heater isn't repairable, the brochure might help the technician sell a better water heater than the cheapest one available, which is what usually happens. Just by knowing they have a choice, many homeowners will opt for something other than the low end.
Technician handouts are good tools for any number of products. An electrical contractor might develop a brochure that offers the benefits of relocating light switches, adding outlets, and so on, emphasizing how simple and easy it is once the technician is already in the home. A carpet cleaning company might prepare a handout on the benefits of their furniture cleaning service.
In the air conditioning business, you could make up technician handouts to promote electronic air cleaners, humidifiers, service agreements, energy upgrades, and setback thermostats. The technician merely has to hand one or two to the homeowner to look at while he works. It gives the homeowner something to do besides look over the technician's shoulder. It also prompts the homeowner to ask about additional products or services.
Even if the homeowner doesn't act today, the handouts start the subconscious mind working. If you do a good job on the repair, they might begin to focus on the benefits of a central humidifier. Desire takes over and they call you back to come out and install one.