I have had a Heatmor 200 since 2005 & seems like the Honeywell aquastat on the low side goes bad about every 6 years or so -I'm sure that bouncing some pieces off the back wall occasionally doesn't help. Has anyone converted to a Ranco style digital controller? I haven't researched it a lot on the probe sizes & how to wire it up. My dealer didn't have any & I picked up the wrong one - maybe I can swap some of the guts? Also its time to clean out the hot water plate - any good products to pickup locally to circulate thru that? Last time it clogged up I took it somewhere to clean it out but installed the valving to do it in place. Last night I used ZEP & seem to work pretty good.