Contact and corrections
Updated
Send a correction, report a calculator problem, or tell us where the site could be clearer.
A public email address is not currently available. The correction guidance below explains what to include once the contact route is available.
Report a product or content correction
Include the page address, product name and US variant if relevant, the statement you believe is wrong, and a link to the manufacturer page or manual that supports the correction. A manual page number or named specification section helps distinguish regional variants and similarly named models.
Report a calculator problem
Tell us which calculator you used, the steps to reproduce the problem, the result you expected, and the result shown. Include units and the relevant efficiency, reserve, and health settings. Browser and device details are useful for a display or interaction issue.
You can describe the inputs in the message. If you choose to send a share link, first remove private device labels: the link contains the plan, and anyone who receives it can read those inputs. Do not send passwords, payment details, account access, or information about a sensitive location.
Accessibility feedback
Identify the page and control that caused difficulty and, if useful, the browser or assistive technology you were using. Describe what prevented you from completing the task. You do not need to disclose a disability or medical information.
Product orders and technical support
For delivery, returns, warranty claims, or instructions for connecting equipment, contact the manufacturer or seller. This site does not process orders or access customer accounts. General planning limitations are explained in the methodology.