We would recommend the ULSA-2 035 as a replacement for your Reznor ECCO 5033B. Please click the link below to view the product. https://www.reznor.co.uk/product/rheco-warm-air-heaters/?selected=3962&pa_kw=2436&pa_fuel-type=2429&pa_range-type=2469
What would be a good replacement for a Reznor ECCO 5033B?
Looking to upgrade your old heater? Look here for information on which product is the best like-for-like replacement.