heater circulation pump problems - hot spring spa

[st18901]

Hey everyone,

It's been a while. That's because my old classic Hot Spring Sovereign has been working like a dream.

But...

last night, I went to go in and the water was cold and the tub was dead.
checked this morning and the heater circuit had tripped. Internal trip, not gfi

Upon resetting it, everything came back to life. However, the water coming from the heater seems to be a lot hotter then before and there seems to be less - like almost no - flow.

Question - could this be my overactive imagination, or - would heated water still be coming out if the circulation pump went bad?

I let it go for about fifteen minutes and didn't trip anything - however, I decided to shut it down and check with you knowledgeable folk first.

Follow up question - how can I troubleshoot the circulation pump?

It's a Laing sm-303-btaw
My tub is a 1986 Hot springs Sovereign.

Any other suggestions?

Thanks!

 

[jfish63]

There should be a sail switch or some type of flow indicator that would prevent the heater from working if the pump was bad. Is there a plug or some means of disconnecting the pump to verify the heater shuts down with no water flow?

 

[hottubdan]

It sounds like you have a circ pump barely working, probably below optimal flow rate.

When heater got too hot it tripped the reset buttom, which is there to prevent further failures do to lack of circulation.

Does your circ pump work with the filter as well as the heater?  If so, it could be clogged filter.

If not clogged filter, I would let it go until total failure.  As long as heater reset working you cannot hurt anything.

If you need to replace, it is pretty simple.

 

[st18901]

Dan,

thanks for the advice. Is there anyone else that can confirm what Dan is saying about letting it go till total failure?
I'd hate to melt anything down that doesn't need melting down.   :'(

The pump doesn't work in conjunction with anything else. it's a 115v tub. Makes life pretty easy, actually. And there's no filtration involved either.

I wonder if there is any way to keep the pump going?- cleaning? etc.

 

[st18901]

Dan, or anyone else -

what replacement circ pump would I use?

This is a 1985/86 'ish Hot Spring Sovereign.

The pump model is LAING SM-303-BTAW

Thanks.

 

[hotubinn]

I would first make sure that the circ pump doesn't draw through the filter.  Many times a dirty filter can be the cause  this type of problem.  If circ doesn't draw through filter, surely is a bad circ pump.  Your hot spring spa does not utilize any type of flow/ pressure sensor. This is a giant problem with hot springs, in my opinion.  They utilize dual hi limits, one sensing water temp in tub and one sensing water temp in heater.   Not uncommon for a circ pump to go bad- then take out the heater.  It is not good for the heater to repeatedly trip the hi limit, which essentially amounts to a dry fire of the heater.  I have witnessed, on more than one occasion, a circ pump take out a heater.  I would identify the problem, and correct it immediately before it is to late to save your other components.

 

[st18901]

well, the heater tripped again -- so

I'm getting another circ pump.

Even after it tripped, the hot water emerged from the outlet for quite some time, so I think the only reason there was any kind of flow was because of temp differential of the water. (hot rises - out - cold sucked in).

damn, and the circ pump was only twenty one years old too.  

Still need to know from someone what model to replace the pump with...
It seems like an SM-303-NH or an SM-303-NTW  would work - but I hope someone can confirm.

 

[hottubdan]

Replacement is the current Silent Flow 5000 or a Laing 303.

If you want my help getting one PM me.

Fact is if heater is high limiting because of failed circ pump, it is not dry firing.  There is water there, just not moving.  Over heates and trips.  Doing its job, protecting the heater.

If heater has never been replaced and goes bad, do not assume it is because circ pump went bad.  It would be 20 years old also.

 

[st18901]

Quick follow up - in case some future diy'er is searching through these forums.

In regards to my 1986 HS Sovereign...
I replaced the dead circ pump with a new laing sm-303 and am back in business.

I found a place called Scottsdale Industrial Pumps in Arizona, with great prices - though I think the prices were a one time deal. They were trying to get rid of old -new stock.

Anyway, I made an offer on a pump that was gathering dust on their shelf because it was missing the cord;  $10.00   ;D
Figured it was no major loss if I couldn't fix it.
Popped it open and pulled the cord off the old pump. boom - about two minutes to fix. Works perfectly, a happy ending to the story.
Fifteen dollars with shipping and I have nice hot water again courtesy of a new circ pump.

I guess the moral of the story is: (if you're a bit handy, and careful with what wire goes where) don't let a missing electric cord be a deal killer on LAING pumps. They are really easy to wire.

That old circ pump lasted 21 years. Not bad.

 

[hottubdan]

You did great.

No cord on the circ pump is standard.  Using cord on dead pump is the norm.

good job!

 

[st18901]

Standard? That's funny.
I feel a bit bad now that I "stole" the pump from them.

Thanks for your help, Dan

 

[bjmsam]

I have encountered a similar problem with the Laing SM-303-BTAW circulation pump in my Hot Spring Spa Classic Model E (circa 1987).  I removed the pump for inspection and found that there isn't much to it; a rotor repair kit would likely do the trick but I can't find one listed without the disclaimer "Laing SM-303 Repair Kit is not to be used with Spa Pumps."  Why not?  $60 seems like a lot for the kit, but it sure beats $150+ for a SilentFlo E5 and 1/2" adapter kit.  Can anyone offer insight?  TIA!

 

[hottubdan]

Most likely the kit is not made to withstand hot tub chemicals, pH, temp, etc.

 

[bjmsam]

This kit and this kit are sold by spa companies without that disclaimer despite looking identical, which seems suspicious.  If the pump cannot be repaired, then I'd like to replace it with one that can; would the SilentFlo E5 be my best bet?

 

[David217]

Question, have a 99 Hotspring Sovereign with like warm water temp. Circulation pump (silent 5000) hums when I have power plugged in. Heater light on ckt brd is lit, however, when I turn on any jet, the heater lit goes off and does not feel like any hot water is circulating.
The main concern that I have (besides no hot water) is the circulation pump hums when plugged in to GFI and circulation pump gets really hot butworks fine and does no trip or shut off due to temp. Please help, thank you! David