Replacing 6kw heater with 4kw

[timbauks]

I’m looking to get my spa back up and running as we are trying to sell our house.  The heating element has gone and need a cheap replacement.  I found an open box No Fault 4kw element for about $300 less than the current heater exact replacement which is a 6kw No Fault.  My question is, can downgrading the element still work?  Will it simply use more power to sustain temp?  Take longer to get to temp?  I’m asking about a Tiger River 2002 Siberian.  Thanks!

[bud16415]

I wouldn’t do it. Besides the obvious reason of misleading the potential buyer and possibly passing on a problem that will make the heater short lived. I’m assuming you are hoping to get more for the home with a working tub as part of the deal. I would sell it as is telling the new owner it needs a heater replacement allowing them to decide or fix it with the correct parts and add it to the cost of the house. A 17 year old hot tub is worth very little even working. The new owner might like that it is wired and has suitable location for a new tub and opt to upgrade anyway.

[timbauks]

Thank you for the reply.  I’m actually asking as to not mislead anyone.  That’s why I’m asking the question.  If it’s going to cause a problem I’m not going to do it.  So I guess this doesn’t answer the question.

[bud16415]

I understand. I would say you should be able to make it work. as long as you have 240v heater and a 240v power source it will heat water. It will just be slower. What I don’t know about is how the circuit is protected for over current and how that will work out. The larger unit of course will draw more power and fusing/breakers would be sized for that size unit. The GFCI aspect of the overall safety should work the same.

I don’t have the expertise to know what is in the control system of the heater and how it will interact with a lower wattage device. Maybe some of the pro members will comment that have a service background and have done retrofits. 

[castletonia]

Only difference is it will heat slower.

[Hottubguy]

Only difference is it will heat slower.

Yep. Must be a single pump tiger river tub with circ pump.

[Tman122]

It won't make any difference in longevity or energy consumption. But it will heat slower.

[bud16415]

Heating slower is a relative thing as if the tub is hot when you get in it and it stays hot while you are in it that’s all that is needed.

A larger heater will indeed last longer as it will be on for less hours and most things have a life expectance based around hours of usage. If the 6k say were to last 6 years the 4k would last 4 years. Factor the life/cost out along with the quality of the cheaper aftermarket unit and the cost savings might not be there.

Now if you are flipping a house and just want it running for the flip that’s a different factor. Like a used car dealer putting retreads on his cars he’s selling.

[SerjicalStrike]

The 4kw element will be fine.  It is typically titanium.  Bad water chemistry affects heating element lifespans way more than run time. 

[Tman122]

Heating slower is a relative thing as if the tub is hot when you get in it and it stays hot while you are in it that’s all that is needed.

A larger heater will indeed last longer as it will be on for less hours and most things have a life expectance based around hours of usage. If the 6k say were to last 6 years the 4k would last 4 years. Factor the life/cost out along with the quality of the cheaper aftermarket unit and the cost savings might not be there.

Now if you are flipping a house and just want it running for the flip that’s a different factor. Like a used car dealer putting retreads on his cars he’s selling.

Because of the lower wattage to run the 4K versus the 6k the life expectancy may be a wash and not worth considering (6K burns hotter less time) (4K burns cooler for longer) toss that up.

Agreed on the tub in the house purchase. Put the lower wattage cheaper heater in and say nothing. Tell them you just put a heater in it and it works perfect.