Blew AUX pump hose after switching on heat/fan

[Aleksey]

I'm just wondering what are schematics behind it or was the timing a pure coincidence. That hose (to my understanding) would have been under pressure anyways so I'm leaning towards bad timing and this has nothing to do with the heater controls.

Definitely forgot to replace that son of a bitch.

Opinions?

[rcsoundn1]

Id say bad timing, they wear out at some point