H.Assoc sent heating engineer as boiler dripping again. He stopped the drip but needed to return next day to fit a new part. Got up next morning to find boiler had flooded all over expensive microwave which was directly underneath on counter top. H.Assoc say not their fault even though boiler was being repaired for drip that day. My insurance company charge £245 excess for water damage claims. Are H.Assoc responsible for their boiler ruining my microwave?