Scorch marks in boiler

[Easydrinker]

Trying to keep the sediment OUT of the boiler is certainly a GOOD thing.
Copper coins or pipe off cuts is also a GOOD thing.
Just ensure that if you use coins that they are genuine copper?
A reason that I only use pipe offcuts.
Not using boil pieces is a recipe for a mess.
Copper ones, IMHO help in the final taste.
Make up your own mind.

Robert.

[Mash]

Also I have not used any coins since and its been fine so could have been that..

Nope. It is crud under coins. Keep the coins cut the crud. Try racking the wash in.