2019 Heartland Sundance 3700rlb

Hi everyone -

We just purchased a 2019 Sundance 3700rlb and are eagerly awaiting delivery. Can anyone tell me the mattress size? It says king but I am assuming RV king which has different dimensions? I find RV mattresses subpar and want to buy a foam topper for it.



Active Member
Even with a topper we found our new King to be subpar, perhaps even terrible and after about a two weeks we had had enough. Check out mattress insider https://www.mattressinsider.com/rv-mattress.html which is where we bought a custom RV King for our new rig. Love it! It's just like sleeping at home. A little bit more $$ but well worth it if you spend months at a time in it as we do. They can make any size you want. Ours came with an RV King, look through their site and they will have all the information on RV mattress sizes. Once we had the new mattress, we opened up the standard (comes with a new rv) mattress and it's no wonder why they are horrible. Two layers of 2" fiber not even foam, it's an interesting project at any rate. I know it doesn't really answer the size question you had but we spent a couple hundred on a topper when we should have just bought a new mattress, just thought i'd pass on our experience.