switch for light also turns on a circulation pump - looks like a 4-way switch - has failed
This sounds like it would use a double pole single throw switch. Each side of the switch would be electrically separate, but they physically turn on and off together. The relay probably just turns on the pump when any of the switches are on. If this were some sort of 4 way setup, turning the light on in two rooms would turn off the pump.
You can test that your new switch is a double pole single throw switch with a continuity tester. All four contacts would be isolated from each other when the switch is in the off position. When the switch is in the on position, you'd have two separate pairs of contacts (probably the one pair on either side of the switch) that have been connected, but there would still be electrical isolation between the pairs. If you want to be extra sure that this is correct, take out one of your existing working switches and confirm that it behaves this way as well.