Pimlico installed my boiler in in 2018. In the subsequent maintenance service have raised a recommendation that the boiler system needs flushing. I raised a complaint with them saying that flushing should have been done at the time of boiler installation and if it was this recommendation should not have come on the invoice. I have been in email conversations with Pimlico for the last 2 months on this and no resolution has been reached. Pimlico today called me and said its just recommendation and to ignore it. Please help resolve this dispute. After spending £6k for an installation, I would expect it to be done properly. They are neither providing clarity on this case nor resolving it. My ask is to investigate what was done at the time of installation and do the flush free of cost to ensure my boiler system is safe for us. I have got all the relevant emails (of the 2 months conversation), invoices (with the recommendation) and original installation checklist (claiming the flushing was done). On the hopes that my request is a realistic one, please help resolve this dispute...