Jump to content

Beachcomber 550X 'OH' (But no overheating)


billajoe

Recommended Posts

Hofully someone can point me in the right direction here...

I have a recently acquired a 2003 550X spa and was aware that there was, and still is, an issue where it shuts down and reads 'OH'.

There doesn't seem to be much of a pattern to this occurring but its fair to extremely consistent.

Initially the spa heats up to anywhere around 34 with no issue at all, then cuts out. Re-sets straight away and continues to heat a little more (display set to 38).

I can get the spa to full temp by resetting each time but then it seems to shut down more frequently.

 

I initially replaced the hush pump - This was needed for more than one reason.

I believe the original owner tried replacing both temp sensors.

And I have checked for air blockages and the filter is new.

 

Any help with what to try next would be much appreciated!

 

One thought... can I test or possibly clean the flow switch easily? Is that worth trying?

Link to comment
Share on other sites

OH means the hi limit sensor is tripping.  The pressure switch tells the circuit board to turn on the heater, so a bad pressure switch that was stuck in the closed position would tell the heater to fire up, even if the water wasn't flowing, which would set off the hi limit sensor.  To check the pressure switch, test for continuity both with water flowing and water not flowing.  the switch should open when the circ pump turns off.

If the pressure switch is good, either your water flow is restricted, the sensor is bad, or the circuit board is having a problem.

First, are you filters clean?  Because dirty filters can restrict flow.

Is the circulation pump running when the OH error comes on?

Dave

 

Link to comment
Share on other sites

Thanks Dave

Im confident I can rule out the filter as it is brand new and looks clean etc. But should I be cleaning the pipe work from the filter too in case there is a blockage?

The OH error only ever occurs when the circulation pump is running. 

I was able to swap out the high limit sensors this afternoon as an old pair were supplied with the spa... I'm guessing the previous owner tried replacing them. Obv. I could have two pairs of faulty hi limit sensors, so can't rule that out just yet.

I'll go and test the pressure switch now but am I wrong in thinking that if this was stuck on, then the water would literally be overheating?

This afternoon the fault seems to have occurred even more frequently. Temp set to 38 but cutting off at much lower temperatures i.e. 32.

 

 

 

 

Link to comment
Share on other sites

Pressure switch working correctly. :(

Can I temporarily bridge this out to confirm that there is not a reduced flow problem? The system is now shutting down in less than a few minutes rather than an hour or so. 

It seems odd to me that both times I have filled it, the tub gets up to a good temperature before I start experiencing any fault. 

Banging my head against a brick wall here!!! Lol

Once again any help would be greatly appreciated 

Link to comment
Share on other sites

If the OH error occurs with the circ pump running and water flowing, than it's not a flow issue.  The easiest way to test the flow switch is to disconnect the circ pump when the spa is running and the heater should turn off within a few seconds.  If the flow switch is in a clear housing, you can see the paddle move when the circ pump comes on.

The fact that the tub runs longer after a fill before giving you a fault tells me that the sensor isn't tripping when the water is colder. 

When you are checking the temperature, are you going by the topside, or are you using a thermometer?   I'm wondering if the water is actually at 110 which is what prompts the OH error.

It is possible you have an obstruction inside the heater tube which is causing one of the sensors to read a higher temperature than the other.  The only way to see that is to open up the heater and look inside. 

I don't know why anyone would save an old pair of sensors.  If they are good, why would you replace them?  And if they are bad, why would you keep them?

 

Link to comment
Share on other sites

So I have now replaced the heating element, the two high limit switches, removed cleaned and tested the flow switch and everything looks good; I also cleaned the pcb front and back to be sure nothing obvious was shorting.

Temp is constant on the display and in the tub - tested with thermometer.

I was extremely hopeful when replacing the element because, it had some damage (bubbling and cracking of the outer coating).

Sadly though none of this seems to have made the slightest difference, and I am still getting the same fault of OH displaying after the tub heats for a short while.

I guess I have no other choice but to replace the pcb now but before I do that I have one confession to make... When fitting the heating element my ratchet spanner slipped and I ever so slightly cracked the protective coating just below the terminal. Have I just replaced a damaged element with another one!? 

The OH fault only occurs when the heater is running for anywhere between 1 - 20 mins.

Again any suggestions or help would be greatly appreciated.

IMG_5063.JPG.de055ff4dac1f5a131f38ad8b353519d.JPG

Link to comment
Share on other sites

The cracked heater would cause the tub to short out, not overheat, so that's probably not your immediate issue.  In the future, as you've seen, you need to hold the bottom nut when you turn the top nut.

I suggest you turn the spa on, sit down in front of the circuit board, and listen to what happens. You're listening for the sound of relay's opening, pumps running and water boiling.

Does the pump shut off before you get the OH error?  If the pump shuts down, then within a few seconds you hear boiling inside the heater can (which will become very warm) then your heater relay on the PCB isn't opening up, which it is supposed to do when the circ pump shuts off.

If everything is running normal and the system just suddenly reports an overheat and shuts down, then your sensors are either giving bad information to the circuit board, or the circuit board has some type of logic problem that's interpreting the information badly.

You can always put the hi-limit sensor into a cup of ice water and see if the OH condition still occurs.

You said the original owner supplied a set of sensors.  How positive are you that the the first set of sensors was bad and he replaced them with the proper part number?  All sensors look pretty much the same.  Are they 2 or 3 wire sensors?  The parts are not interchangeable.  Could it be time to purchase a new set of sensors, going by the circuit board chip number and spa number, instead of using questionable parts, or are you positive you have good sensors?

 

Link to comment
Share on other sites

Really appreciating your input here.... let me know if you ever have a problem with any automated gate system, I might be able to return the favour! 

I'll sit down later and try just what you have said. I agree with you about the sensors, I needed to rule out any work the previous owner did, so I have already replaced the sensors with the correct type. However I might just double check they were the right ones, because you're right, I just ordered a new pair using the same part code. 

 

Link to comment
Share on other sites

So with or without the sensor(s) in 16degree chilled water the hush pump kicks in first, then the heater turns on. System runs for anywhere between 1-10 mins and then both the heater and the hush pump switch off as the relay clicks. 

Display reads OH. 

No unusual noises at all and heater warm but certainly not hot. 

Sensors are two wire. 

Main pump has now just kicked in on max (for 20-30secs) as I'm still sat here. Not sure it's done that before? Coincidently maybe?

30seconds later it's just done it again. Display remains reading OH. 

 

Link to comment
Share on other sites

Just to clarify what type of control system you have - is it a Balboa control pack?  If so, the circuit board would be in a moulded plastic case, screwed together at the top, and the heater can would be in the bottom of the case.  The sensors would be screwed into the heater can, one on the left and one on the right.  Is that what we're talking about?  If so, how are you putting the sensors in cold water without having water spraying out of the tube?

If the system gives an overheat error when the sensors are in cold water, then I doubt the issue is with the heater or circulation pump. 

With the hi limit sensor disconnected from the PCB, I would expect the system to shut down, not turn on both pumps.  That sounds like an erratic circuit board.  If the problem is bad sensors, you usually get one of a variety of Sn errors.  Still, a pair of sensors is a lot cheaper than a new circuit board.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Unfortunately, your content contains terms that we do not allow. Please edit your content to remove the highlighted words below.
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
×
×
  • Create New...