Expansion / Contraction of A/C - Heat Pump Popping????

[Bob & Mary]

We have a 2017 31SL and have a noise that I can only describe as "large drops of rain" hitting the roof. The sound that the large scattered rain drops make, just before a really hard rain storm arrives. We hear it when the heat pump shuts off. The noise continues for quit a few minutes afterwards. We think it started last year, but it was much quieter and more subdued, more like the sound of a squirrel walking around on the roof and we noticed it when the A/C would cut off.

We are using the RV this week during our spring break. The weather is cool, lows in the upper 30's/low 40's, and we are running the units in heat mode and the noise is much louder, like big rain drops. I would guess that it is related to expansion and contraction of something in the roof, but what? Is anyone else having this issue? Or is this just our unit? It's becoming quite annoying.

For additional info, we are weekender's, if that's a word, and this is the first week out this year. When we are not using the RV it is stored in our shop which is not climate-controlled.

[RWJSIM2003]

That sound is the water running out of Heat pump. Ours makes the same noise has since new.