According to baxi website sp3 is not compatible with 553, but you can use VP3 Natural Gas Propane Gas Renewal Baxi Bermuda SP3 G.C.No. 37 077 63 Baxi Bermuda VP3 G.C.No. 37 077 62 For use with the following boilers: Baxi Bermuda 45/4 M G.C.No. 44 077 71 Baxi Bermuda 45/4 E G.C.No. 44 077 73 Baxi Ber...
