Time to bin letters making dubious solar claims

Messages appear to be a ruse to get people to sign up to unnecessary services

We have had solar panels on our roof for some years and all is working well. Last week we received a letter from the British Trading Solar Association warning us that the five-year warranty on our inverter was due to expire. It invited us to book a free health check and service. I have never heard of the BTSA and it did not install our system. Can you shed any light on this?
PI, London

In March this year the Microgeneration Certification Scheme issued a warning about these letters, and told people to bin them. They appear to be a ruse to get people to sign up to unnecessary services or similar. I'd suggest you follow this advice.