Hotspring heater OHM reading

[Harryone]

Hi Guys, 

Wondered if any one can advise. 

My second hand 2006 Hotspring Jetsetter original No-fault 1.5kw heater sprung a leak from one of the barbs that screws into the main body of the heater (Barb crumpled on touch), so I took heater out to examine and did an ohm test to see the quality of the element (tested black and white connectors. Followed a YT video on how to do this). The reading was constant 36.6ohm on two separate volt meters.

My question is I believe a good read would have been 8-20ohms. A 0 or near read would mean throw the heater in the trash, but what does an above 20ohm read mean? I can replace the barbs for 40 pounds (£ - I am in UK), put back in, fill with water and fire back up, but don't want to waste my money and time if a new heater is the only way forward (new heater being model 76229 @ 560 pounds! )

I unscrewed the end of the heater and looked inside both of the titanium tubes and everything looked really quite clean. Literally no fur build up at all. As I said I bought second hand and can only think the Spa had quite soft water running through it all its life. (seems a shame to throw the heater based on looking at it only as it is really clean and these things aint cheap!) 

My IQ2020 circuit board looks fine and I cant see any burn marks etc. (see pics attached for the more eagle eyed)

Appreciate any feedback.

Cheers

[RDspaguy]

Doing the math, a 1.5kw 240v heater should have about 38 ohms resistance.

[Harryone]

4 hours ago, RDspaguy said:

Doing the math, a 1.5kw 240v heater should have about 38 ohms resistance.

Ah. didnt think about that! Looks like the old heater might have some life left in it afterall with a read of 36.6 ohms.

Will order up some new barbs and see what happens before splashing on a new heater. 

Can I ask how you did the math RDspaguy as would be interested to know how these things are calculated?

Many thanks!

[RDspaguy]

Ohms law, the basis of electrical theory, says:

Volts = amps x ohms

And

Watts = volts x amps

If you apply a little algebra, you can figure any two unknowns with two knowns. You provided watts (kw) and volts is known. From that you can derive amps, and with amps and volts you can derive ohms. 

[Harryone]

New heater arrived, did an OHMs test and bang on 36.6ohms - same as the old heater. Happy days. Will send the new heater back and get a refund after I have put in the new barbs in old heater and given it a try. Fingers crossed all sorted. Thanks for your input @RDspaguy much appreciated. Hopefully the old heater still has some miles left in it 👍

[Harryone]

@RDspaguyAh looked like my plan didnt work 😟

Did what i said which was to replace barbs/red O rings. Also decided to put new Thermistors on in case there was a fault with one of the old ones. Refitted the heater, filled the tub down through the circ pump filter end (filter off) and switched the tub on. Circ pump works within 10 seconds or so and Ozone bubbles seem to flow strongly upwards. Control panel bezel has nothing other than flashing red light. Main Circuit board shows the below lights:

LIM light off

HTR light on - but it doesn't feel warm even after 10mins of being on. Control panel bezel shows no temp reading or anything in the little window

CONTROL UNPLUGGED light is on.

there is another red light under the big yellow transistor thing, but I dont know what that is.

What is the LIM light? I thought it was the Luminescence light indicator, but have a feeling it is a bit more important than that!

Here is a pick of the relay board. Cant see any burn marks if that might be a reason..

Any advice greatly appreciated..as Hotspring Service Techs here in the UK are super busy and ideally I would still like to solve myself?

Thanks H 

[RDspaguy]

The lim ok light is the high limit indicator, and it should be on.

It appears that the pressure switch harness is off center on the plug.

I don't know what the light below the small "daughter" board is. Maybe @castletonia knows?

The control unplugged light should not be on, and often indicates a bad control.

That said, I notice on the left side of the yellow cylinder on the daughter board a fuzzy brown spot that I don't think should be there. This leads me to believe that you may need a board.

@CanadianSpaTech, your thoughts?

[Harryone]

Strange the high light indicator is off when it is a new high limit thermistor in the heater? would have thought that would have come on being new.

Ive taken a closer shot of the yellow cylinder and it does look fuzzed up when compared to a picture of a new one I found on the net. Would you bet on this being something to do with it?

I am not sure if this played a part, but when the electrician came to fit the outdoor power I asked him to do a volt meter test on the circuit on the Luminescence LED to see if it was fixable as didn't work. In the process I think he may have shorted something as there was a very small spark from the LED when he tried to test it and then nothing would work on the control unit!   at that point I hadnt taken a picture of the motherboard so dont have a before and after picture 😞

@castletonia@CanadianSpaTech@RDspaguy appreciate any further input you have guys before I take the plunge and spend more on the spa. 🙏 

[RDspaguy]

My money is on the circuit board.

[Harryone]

On 3/11/2021 at 3:58 PM, RDspaguy said:

My money is on the circuit board.

@RDspaguyDo you know if the transformer can be tested without removing with a multimeter?

[RDspaguy]

Not on an IQ pack that I know of.

[Harryone]

@RDspaguy Can you tell me how I test the pressure switch on my Heater to see if that is at fault (before spending big dollar on a new motherboard)? I know you said it can be jumpered in your past comments i have seen on the site.

I have the new heater now, but dont want to plug it in and use it if the old heater is OK. Would rather fully test the old heater which has good element (OHMS test) and new Thermistors. If the pressure switch is not the issue then i know the heater is good and i can return the new one for refund. I then know it has to be the control panel (which i took apart and looks all good, but maybe just isnt or indeed the PCB. Thanks again for your advice 👍

 

[RDspaguy]

Do a continuity test on it. It should be closed (0 ohms) when pump is on and open (no reading) when off.

That system is not smart regarding the pressure switch, meaning you can jumper it by connecting the pins on the board and it will work.

If the heater ohms out and is not tripping the breaker, it is good.

I have little doubt that it is the board.

[Harryone]

4 hours ago, RDspaguy said:

Do a continuity test on it. It should be closed (0 ohms) when pump is on and open (no reading) when off.

That system is not smart regarding the pressure switch, meaning you can jumper it by connecting the pins on the board and it will work.

If the heater ohms out and is not tripping the breaker, it is good.

I have little doubt that it is the board.

@RDspaguyJumpered the heater pressure switch tonight and no difference to lighting arrangement.(see photo) Still no LIM ok light and still Control unplugged light on. I then went looking for other faults. Took control panel out and examined back and front and couldn't see any fried parts. Control cable to motherboard was all good. Also flipped Relay board over and looked for burns, but all good. Really scratching my head with this one! Might take the whole IQ2020 to a electronics shop and see if they can see what is wrong. 😞

[RDspaguy]

It's that yellow cylinder on the daughter board with the brown stuff coming out. Not sure they can fix it without removing the daughter board, which I am not sure can be done.

Keep us posted.

[RDspaguy]

I think @spokanespasdoes circuit board repairs, maybe he can help.

[Harryone]

19 hours ago, RDspaguy said:

Do a continuity test on it. It should be closed (0 ohms) when pump is on and open (no reading) when off.

That system is not smart regarding the pressure switch, meaning you can jumper it by connecting the pins on the board and it will work.

If the heater ohms out and is not tripping the breaker, it is good.

I have little doubt that it is the board.

@RDspaguyI do believe I may have found the problem....circled in red. Am thinking that looks melted and cant be fixed which = a new control panel.

My concern is if I replace with a new control panel am i asking for trouble again if the leaky transformer capacitor burns the new control panel out.

[RDspaguy]

Looks like a manufacturing mark to me. I'll pull one apart later and check for it, or maybe @castletoniahas one laying around.

[RDspaguy]

@castletonia, do they still make the controls from 2006? Or is he looking at a full system, whether it's the board or topside?

[Harryone]

11 minutes ago, RDspaguy said:

@castletonia, do they still make the controls from 2006? Or is he looking at a full system, whether it's the board or topside?

I can still buy this control part from the USA. https://www.backyardplus.com/proddetail.php?prod=73225 but will add over $100 for duty, import taxes etc..

[Harryone]

1 minute ago, Harryone said:

I can still buy this control part from the USA. https://www.backyardplus.com/proddetail.php?prod=73225 but will add over $100 for duty, import taxes etc..

 

[castletonia]

22 hours ago, RDspaguy said:

@castletonia, do they still make the controls from 2006? Or is he looking at a full system, whether it's the board or topside?

To my knowledge everything from 2006 is still available.

[Harryone]

@spokanespas @RDspaguyHad a motherboard repair shop replace the big yellow capacitor today on a no fix no fee outcome, but unfortunately didn't work. He checked all the other capacitors on the daughterboard and all were ok.

Thoroughly checked the control panel and the microchip within (previous pictures) had just got warm, but hadnt burned out. Cable to motherboard was in good condition.

Also checked the heater relay front and back and all in order. no heat or burn markings anywhere

Jumpered the pressure switch too to see if that made a difference and nothing. 

Am really purplexed now as to what the fault is without spending 100's on new motherboard and new control panel.

Any further ideas guys?

 

[RDspaguy]

Unfortunately, that's where we are at. No limit ok light, control unplugged light, new thermistor, and good control connection. It can only be the board or control. I thought for sure it would be the component on the daughter board, which is the low voltage power supply. I wish it had been.

You can try hot springs support to see if they can narrow it down, but I suspect they will recommend both.

[Harryone]

@RDspaguy@castletonia Took the plunge and drove an hour down the road to the Hotspring dealer warehouse and bought a new control head and motherboard. Went home, swapped out the old motherboard for the new one. connected up the old control head and no lights on the control head at all. Only lights on motherboard are: HTR ON off, Flashing CONTROL UNLUGGED and Flashing green LIM OK light.

Thought well it must be the old control head too that is broken, so swapped the control head for the new control head and nothing again. no different to the old control head. Jumpered the heater to see if that made a difference and nothing. Any ideas guys?

Just as a reminder filters are out. Circ pump was running fine and strong with the old motherboard, but isnt with the new one. Heater relay shows no signs on front or back of any damage/burns. I have new Thermistors on the heater and the heater was reading the same OHMS as the new heater which i still have in a box in the house.

Can only think it is a power thing. Any ideas guys before i pull out the little hair I have left on my head!?