The Heppen Mill (also known as Mill Zels) was a wooden windmill in the Molenbergstraat.
The default mill was founded in 1853 by miller Felix LOOS from Balen, who transferred the mill elsewhere.
His children took over the mill in 1862. In 1878 the mill was put on the name of Leopold LOOS (for 3/5), Monica LOOS (for 1/5) and Mathilde LOOS (for 1/5).
In 1880, Leopold LOOS had the complete mill property on his name.
He sold the mill in 1883 to miller Jules VERBEECK-VERHEIJEN, who in turn resold it to Eugeen DEMOLIN-JORDENS, who died in 1909. His widow and children kept the mill until WW I. The tenants were Peter THYS and Alfons ZELS.
Heppen counted about 900 inhabitants in 1914, who lived mainly of agriculture. On August 7 1914, 5 days after the start of the war, Belgian Rijkswachters (national guardians) occupied the school premises behind the town hall of Heppen. On August 14, a German patrol German arrived in Heppen. There was a firefight between the National Guardians and the Germans. One German soldier and two horses were shot dead. The Germans flew away, but on August 17 they returned and this time the National Guards flew(in the direction of Antwerp). On September 26 1914, the Germans set 11 houses and the mill in fire out of revenge. The last remains were cleaned up in 1916.
After WO I, Alfons ZELS continued grinding with the engine. He bought the Leopoldsburg stone windmill in 1927 for the sake of his son Gerard ZELS.