Heater problem Bengal

[PotomacG]

My Tiger River Bengal (2005) had quite a bio-mass build up in the spa plumbing. 

I used a bottle of Spa-Purge per manufacturers directions.  After running the Jets and then letting it circulate overnight (with filter removed), I performed a regular drain and fill.  I did not notice much gunk at all during the draining process.
When I powered the spa back up, I noticed that there was no water circulating.  I had left the Summer-Timer on.  I think this is why the spa purge didn't do much of anything (not circulating over night).
Now the heater is not getting very hot.  The water stays luke-warm even though the unit is calling for heat.

Could the heater have gone bad due to the gunk?  Or could the gunk still left be causing the heater problem?

Before I have the heater replace, I was thinking of doing another purge.  Any suggestions?

Thanks.

John

[hottubdan]

Can you remove circ pump and manually clean it?

[PotomacG]

hottubdan,

Wouldn't removing the circ pump require me to drain the tub completely?  I would think a large dose of spa-purge or spa-flush (carefully monitored this time) might do the trick.

The heater is still working, however, it only keeps the water in the mid 90's and never reaches set temp.

Can any of you pro's out there chime in?  Should I just replace the heater at this point?  If it reached the "set temp" I would expect it to be a bad thermostat, but the "spa ready" light never comes on.

Also, can you replace the heater without draining the tub?  (I believe I can clamp of the line from the pressure switch, I'm not so sure about those 1 inch lines going from the circ pump to the heater and back.  Can they be clamped off, or does only a limited amount of water come out with the power off?

Thanks...

[Bonibelle]

I think Dan qualifies as a "pro" 

[Peteyboy]

Dan is a pro. Anything he suggests I for one recommend following.

You can use wine corks to plug the hoses.

I would make sure the circulation pump is pushing water. If you have ozone you should see bubbles coming up from the bottom drain. If no ozone look for a ripple on top of the water above the bottom drain. Pull the filter out to make sure it's not impeding flow.

Is temp or ready flashing on the display?

Your heater may have a reset button on it. The newer ones don't. If you want to test you can unplug the heater wires and test for continuity across the black & white. If you don't have continuity then check the reset button, it will click when pushing on it if it's tripped. If you have continuity then check for AC voltage across the terminals you took the heater wires off of. If you have power there then you need a new heater. If you have no power there and you see a red LED lit on the circuit board where it says Heater On then you have a bad heater board.

The circulation pump can create friction heat that can keep the spa in the 90's.

You talk about bio-mass - If the hoses are just discolored don't worry about that.

[PotomacG]

I never said that Dan wasn't a pro. (Sorry for my wording)  But my question of removing the circ pump without draining the tub was never answered.

Peteyboy:

Nothing flashes on the display and the ready light never comes on.

The heater is one of the newer models with no reset button (sigh).  I have already checked the voltage (220 is there).

I will check the continuity of the main leads to the heater.  (I think the heater is shot at this point).  Can you tell me how many ohms of resistance I should expect?

I do have circulation and the ozone is running as well (just no heat).

If the heater passes the continuity check, is it a possibility that it is clogged?  (and can be cleaned out?).

Thanks to all who have replied.

[Peteyboy]

I never said that Dan wasn't a pro. (Sorry for my wording)  But my question of removing the circ pump without draining the tub was never answered.

Peteyboy:

Nothing flashes on the display and the ready light never comes on.

The heater is one of the newer models with no reset button (sigh).  I have already checked the voltage (220 is there).

I will check the continuity of the main leads to the heater.  (I think the heater is shot at this point).  Can you tell me how many ohms of resistance I should expect?

I do have circulation and the ozone is running as well (just no heat).

If the heater passes the continuity check, is it a possibility that it is clogged?  (and can be cleaned out?).

Thanks to all who have replied.

I'm sure Dan doesn't take offense. The wording WAS a little off.

I don't know how many ohms - I use a beeper. ANYONE?

You can use the wine corks to plug the 3/4" hoses to the circ pump or heater. The heater has a 1/4" bleedline so you have to also plug that - I just use a phillips screwdriver.

If you have plenty of bubbles coming up the heater shouldn't be clogged. If it is the heater that has the power down, power up reset it should be 2 stainless tubes. If it is a long black heater or one that is shaped like a trumpet then it does have a reset button.

If you have 240 VAC at the heater terminals, the heater doesn't have a reset button, you've reset the power and still no heat then it looks like it's time for a new heater.

Again - any discoloration of hoses is normal and I wouldn't flush it.

[wmccall]

I will check the continuity of the main leads to the heater.  (I think the heater is shot at this point).  Can you tell me how many ohms of resistance I should expect?

My background is electronic engineering  and I've never measured one of these, but I'll take a guess and see who yells at me for it.  Most heaters seem to be 4.5kw so if they take 220, that would be around 20 amps.  So 220volts drawing 20 amps would give a resistance of around 11 ohms, but that would be based on DC properties, but it should be close.  If you see no continuity its shot, anything less than 50 ohms is probably ok.

For what little its worth.

[Peteyboy]

No yelling from me Bill. That sounds about right.

[PotomacG]

Right on Bill.  How does 10 ohms sound?

So my heater checks out OK.  My control board does not however.  

The 240v terminals that the heater connects to are putting out about 30 volts.  I'm sure that the tub is calling for heat since the red heater light on the main control board is lit.  

So now I am glad I don't have to buy a heater.  It would seem to be the heater relay board instead.  

Thanks for all the replies.

[Peteyboy]

Yes, the heater board will put out about that voltage when it is bad. You will probably see burning between the relays or on the back of the board when you take it off.
The part number for the board is 74618.

[PotomacG]

The new board is in and the tub is heating!

Peteyboy, there was burning on the back just as you said there would be. 

Do you know what it is that causes these relay boards to fail?

Thanks.

[Peteyboy]

I think it was a design problem - I've never seen a new board have a problem.

[TubsAndCues]

Could be an air lock if the tub was not filled through the filter stand pipe i.e. hose just draped over the side.