We would recommend the PHOTON 120 as a replacement for your Benson GUH 480. Please click the link below to view the product. https://www.reznor.co.uk/product/photon-warm-air-heaters/
What would be a good replacement for a Benson GUH 480?
Looking to upgrade your old heater? Look here for information on which product is the best like-for-like replacement.