Give the technician the observed order
Write down what already happened: the thermostat asked for heat, the small fan began running, the igniter did not visibly glow, and heat did not start. Add any code available through the normal display or viewing window. Do not open a burner compartment to look for glow.
Tell the service company whether the fan runs continuously, stops after a while, or restarts. Include prior repairs and whether the problem began after weather, maintenance, or control changes. Do not keep cycling it to measure exact timing.
We recommend preserving the fault information and requesting a sequence-based diagnosis. A list of possible parts is less useful than knowing which required condition was not met.
What professional testing should answer
Ask whether the furnace is reaching the ignition command and what prevents the next step. The qualified technician can choose the electrical, ignition, venting, drainage, and protective-control checks appropriate to the model.
A pressure-switch-related fault needs its cause established. It does not automatically justify replacing the switch. Ask whether the switch response matches the condition measured and whether the installation or another component needs attention.
Do not bypass a switch, disconnect a tube, or apply pressure to make the furnace advance. A test that forces the next stage does not establish safe operation.
What a useful repair record includes
Request the confirmed finding, the work recommended, and the full repair price. Afterward, ask what operation was verified and whether the underlying cause was resolved. “The igniter glows now” is an observation, but the household needs the complete heating function checked.
If heat will not return promptly, discuss the current indoor temperature and the household's waiting plan. A cold home may require another place to stay, not a longer series of attempts to get the furnace through its checks.
Your next action is to report the small-fan/no-glow sequence and safely visible fault, then arrange professional diagnosis before ordering an igniter or protective switch.