Seeking advice on used 2007 Sundance Marin

[bolds18b]

Hi - first time poster but thanks to all for this great forum!  I'm looking at buying a used 2007 Sundance Marin, which, to my uneducated eyes, looked and felt great (I wet tested tonight).  A few questions:

1) Is $3K a reasonable price for a 6-year old unit? 
2) When I got there, it was set at 99 degrees.  It was about 40 degrees out, and I immediately turned the hot tub up to 103.  The heater light went on, indicating it was heating.  But 45 mins later, the temp had just changed to 100 degrees (then we left).  Is that normal, or indicative of a problem?  With a 220 line, I thought my research said it should heat 6-8 degrees per hour, so this scares me.
3) Can anyone confirm that, when the jets are running, the 2007 Sundance Marin heater still works?  That is, with a 220 line, I'll be able to use the jets and keep the temperature high at the same time?  I live in Boston and envision using this for an hour or two in any given evening in the winter.  If the heater stops when I have the jets on, it will cool down quickly.

Thanks so much for the advice!  I feel bad calling a dealer with these questions, since I'm buying used, so appreciate your input.

[Tman122]

When you say cool down quickly you are on the right track. With the cover on and sealed you can get 5-8 degrees per hour of heating but with the cover off and the jets on high while you were using it the fact that it heated only one degree tells me the heater will keep up.

[bolds18b]

Thanks - that's helpful.  I only had the jets on for a couple minutes...can you confirm that the heater will work while the jets work?  I'm assuming yes, because it's a nicer model with a 220 hookup so I'd be surprised if the heater had to turn off while you were working the jets. But this has been tough to confirm with research. 

Basically what I'm worried about is buying a hot tub, setting it to the temperature I want, and then every time I use it I only get 20 mins at that temperature before it drops.  That'd be a tough surprise.

[Tman122]

Sounds to me like the heater is working. You got one degree of rise during your use with the jets on. With a 220V hook up your heater will be able to work at the same time as the jet pump. Now depending on the amperage of the line you may loose the heater if it's a 2 pump system when both are energized.

[mjb]

The Sundance Marin has two jet pumps (and a blower).
If you were running both jet pumps on high speed and
the spa has a 50A breaker the heater will not turn on.
If you install a 60A breaker and make a pin adjustment
on the circuit board, you may run both pumps on high
speed and the heater will be able to operate at the
same time.