Actually, the only three differences between the -10 heated and -20 heated/regulated probes are:
1. The -20 regulates ON THE GROUND.
2. The -20 contains circuitry to inform of heater status.
3. Price and installation complexity.
In the Jets we use pitot heat rain or shine every flight t/o to landing. But I would argue it?s a seldom used item in light pistons so maybe not where you need to spend extra money for extra complexity....
2.2.1.1 GAP 26 Power Requirements
The 010-01074-00 version of the GAP 26 does not require power as it does not have a heater. The initial current vs temperature requirements for the 010-01074-10 and 010-01074-20 are listed in Table 2-1. See Section 5.5.2 for acceptable wiring configurations.
CAUTION
Do not connect the heated/regulated version of the GAP 26 (010-01074-20) to 28 VDC. The heated/non-regulated version of the GAP 26 (010-01074-10) may be connected to either 14V or 28V. See Section 5 for wiring information.
Table 2-1 GAP 26 Initial Current Draw vs Probe Temperature (-10, -20 units only)
Probe Temperature -40?C (-40?F) 0?C (32?F) 50?C (122?F) 100?C (212?F) 175?C (347?F)
Amps 12 Amp 9.25 Amp 7.3 Amp 5.85 Amp 4.36 Amp
Table 2-1 refers to probe temperature at initial turn-on. For example, upon turn-on at -40?C, the standard (-10) or regulated (-20) heated probes will initially draw 12 amps, but will draw less current as they warm up.
The -10 non-regulated probe draws current proportional to the probe temperature as shown in Table 2-1.
The -20 heated regulated probe uses similar power to the -10 probe when airborne, but will limit the current to regulate the probe temperature to ~75?C (167?F) when the probe temperature reaches this value.