Lennox Furnace Repair: SLP99DFV Communication Faults
If you smell gas or a CO alarm sounds, leave the home and call the gas utility or 911 from outside.
For Lennox SLP99DFV furnace repair, call an independent heating contractor and record the complete E-prefix display. This control distinguishes device communication from blower communication and a blower that cannot start. Supply the exact model and error history so a motor, module or control is not selected by guesswork.
Talk to a contractor about your Lennox furnace
Call (877) 565-3062One call reaches a contractor registered for your ZIP; ask the fee and the arrival window.
HVAC Responder is an independent referral service and is not affiliated with or authorized by Lennox.
HVAC Responder Editorial Team · Reviewed 2026-11-01 · Facts quoted from manufacturer documentation
SLP99DFV communication has more than one failure path
E105 concerns communication between devices; E201 concerns communication with the indoor blower motor. Record both if they appear together and preserve their order. The service conversation should identify the communication path before reducing the complaint to a generic blower or board replacement.
According to Lennox SLP99DFV installation instructions (100002a):
Device communication problem - No other devices on BUS (Communication system). Equipment is unable to communicate. Check for mis wire and loose connections and check for a high voltage source of noise close to the system. (welder etc.).
Indoor blower communication failure - Unable to communicate with blower motor. Indoor blower communication failure including power outage.
A blower that cannot start is separately documented
E292 names a blower unable to start and refers to a seized bearing or stuck wheel. That is a different diagnostic entry from communication loss. Ask the contractor to separate mechanical obstruction, motor operation and control communication while keeping the actual equipment configuration in view.
The Lennox SLP99DFV installation instructions (100002a) also explains:
Indoor blower motor unable to start - Seized bearings, stuck wheel, etc. Indoor blower motor unable to start (seized bearing, stuck wheel, etc), replace motor or wheel if assembly does not operate or meet performance.
Discuss your Lennox furnace with a contractor
Call (877) 565-3062One call reaches a contractor registered for your ZIP; ask the fee and the arrival window.
Product category and model applicability
The manufacturer catalog identifies the product category below. The service examples on this page are limited to SLP99DFV integrated control. Compare the full installed model with the cited manual before applying a signal or component description.
In the document “HVAC Products | Lennox”, Lennox lists this equipment under its Furnaces
category.
Lennox warranty information to check
Lennox’s warranty page separates product tiers and describes registration-dependent options with jurisdiction exceptions. The model, installation or closing date, registration and chosen coverage matter. Ask for a coverage determination and a separate description of any labor or diagnostic charges.
According to Lennox Product Warranty | HVAC System Warranties:
eligible equipment must be registered within 60 days of installation
What to tell the contractor
Read SLP99DFV and all suffixes; record E105, E201 or E292 exactly as displayed, thermostat messages and whether the blower moves before the fault.
Related repair and diagnostic guides
What happens when you call about your Lennox furnace
- Your call routes to an independent local contractor registered for your ZIP code.
- Ask the fee and the arrival window.
- The decision to hire stays with you.
One call reaches a contractor registered for your ZIP; ask the fee and the arrival window.
Sources and review date
- Lennox SLP99DFV installation instructions (100002a), PDF · Captured source reviewed 2026-11-01
- HVAC Products | Lennox · Captured source reviewed 2026-11-01
- Lennox Product Warranty | HVAC System Warranties · Captured source reviewed 2026-11-01