LND Anchor Output Errors - Fix Reserve and CPFP Fee Bumping Issues

What Are LND Anchor Output Errors?

Anchor outputs are small 330-sat outputs added to commitment transactions, allowing fee bumping via CPFP after broadcast. Errors arise when anchor reserve is missing or CPFP fails.

Common Errors

• not enough funds to cover anchor reserves
• cannot sweep anchor: no utxo available
• anchor_reserve exceeded wallet balance
• failed to bump fee: CPFP transaction rejected

Fix: Fund Anchor Reserve

# Check wallet balance and reserve
lncli walletbalance
lncli wallet anchors

# Send on-chain funds to cover reserve (10000 sats minimum)
lncli newaddress p2wkh
# Send sats to this address from external wallet

Fix: Manual Anchor Sweep

# List sweepable anchors
lncli wallet anchors

# Bump fee on anchor manually
lncli wallet bumpfee --sat_per_vbyte 20 <anchor_outpoint>

Prevention

• Keep at least 100k sats in on-chain wallet for anchor sweeps
• Monitor wallet balance with alerting (Prometheus + Alertmanager)
• Use anchor channel type (default in LND 0.13+): --protocol.anchors

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