It's going to be a bu99er to get the condensate trap out of the bottom to clean it on a service, and I'd have lagged the condensate to prevent freezing. A Spirovent on the flow above the boiler would have been good too, to remove dissolved air and further reduce the risk of system corrosion
Thanks. I think there’s plenty of room to do that. I noticed the trap when I was looking under there to get the two front panel screws out. I take your point about lagging the condensate and I’ll look into the Spirovent you mentioned.