Pennco 15B 61 — Line Voltage Unstable
61
Line voltage unstable. The line voltage is unstable, possibly because too many heavy loads are switching on and off; check the branch circuit current draw and the incoming house power. The table classifies it as Error.
Applies to
This fault code is displayed by the Resideo integrated boiler control (numeric error codes) on 15B-K models (15B-060K through 15B-235K), as documented in Pennco 15B Cast Iron Gas-Fired Boiler Installation, Operation & Maintenance Manual, PN 240012786 Rev. D (08/15/2021), Appendix A Table A2 Troubleshooting Error Codes (Resideo control) (240012786 Rev. D). Codes can differ between controller generations, so always check the manual that matches your unit.
- Pennco 15B-K
- Pennco 15B-060K
- Pennco 15B-095K
- Pennco 15B-120K
- Pennco 15B-150K
- Pennco 15B-175K
- Pennco 15B-205K
- Pennco 15B-235K
Controller: Resideo integrated boiler control (numeric error codes). Source manual: 240012786 Rev. D (2021-08-15).
Why a code is not a diagnosis
The code reports the condition the control detected; the underlying cause must be confirmed on site by a licensed technician using the manufacturer's procedure.
Safe things to observe
- Note the exact code, when it appears and what the appliance was doing.
- If the appliance has stopped, call a technician rather than repeatedly restarting it.
- If you smell gas, stop, go outside and call your gas utility's emergency line or 911 before anything else.
Do not
- Do not ignore a code that returns after a reset.
How professional service helps
- A licensed technician diagnoses the cause with the manufacturer's test procedure.
- Combustion and safety devices are verified with an analyser and the manufacturer's procedure after any repair.
Where ROMA provides on-site service
On-site service is currently offered in Greater Vancouver, BC, including Vancouver, Burnaby, Richmond, Surrey, Coquitlam, North Vancouver, West Vancouver, New Westminster, Port Coquitlam, Port Moody, Delta, Langley, Maple Ridge, Abbotsford, Chilliwack, White Rock, Pitt Meadows, Tsawwassen, Anmore, Lions Bay, Belcarra, Bowen Island, Mission. Everything else on this site is reference information you can use anywhere in Canada.
Frequently asked questions
Can I clear this code myself?
Clearing a code without fixing its cause usually just brings it back. Note the code, check the safe items on this page, then call a licensed technician. If your appliance manual describes a user reset for this exact code and it stays away, no call may be needed.
Boiler locked out? Call with the alert text ready.
The brand, model and this alert are passed along when you request service online, so the technician arrives prepared.
On-site service in Greater Vancouver, BC. ROMA lists “Open 7 days” on its site; call to confirm same-day availability.
Sources and verification
- Pennco 15B Cast Iron Gas-Fired Boiler Installation, Operation & Maintenance Manual, PN 240012786 Rev. D (08/15/2021), Appendix A Table A2 Troubleshooting Error Codes (Resideo control) · 240012786 Rev. D · accessed September 9, 2026
Facts checked September 9, 2026. Last updated September 9, 2026. Technical reviewer: not yet assigned.