MasterTemp 250 - E05 error

[Ukiwis]

Suddenly my heater is no longer working.
I turn on spa mode and it fires up but within 20 or so seconds secs gives an E05 error on the panel and the service.

I replaced the stack flue sensor with a spare I had lying around but the problem persists and in looking around there seems to be a blown capacitor on the board.



So, I could try replacing the board but I'm wondering if it might be time to just replace the entire heater.
It is now 11 years old and it might be time to pull the plug on it.

If I replace it, is it worth going to a Mastertemp 400, assuming the gas supply can support it, or am I better sticking with a 250?

When it works the 250 heats the tub around 36 degrees an hour and the pool around 2 degrees an hour. Would a larger heater speed that up or introduce other issues?

Here's the natural gas line. The meter is probably over 200 feet away and it looks like it's a fairly large pipe below ground.



TIA
KIWI

 

[ajw22]

A 400 will heat your pool or spa about 1/3 faster then the 250. You need to decide if that benefit is worth the cost difference between the heaters. In operation the gas usage to heat will be the same.

What is the CFM of your gas meter? Post pictures of the gas meter data plates.

 

[Ukiwis]

This is the only thing with numbers on it.

 

[ajw22]

The meter is probably over 200 feet away and it looks like it's a fairly large pipe below ground.

You should have a big gray box somewhere on the side of your hosue with gas pipes running into it that looks something like this...

 

[Ukiwis]

I do not have one of those. It's fairly small to be honest and hard to get to as it's behind a bush.

At the bottom of the stalk on the right is a plate that has been painted over. The writing says So Cal Gas Co but I cannot make out the numbers below it.

 

[ajw22]

Okay, your grey gas meter is painted over.

I think this shows your gas service has a capacity of 500 - 800 CFM which can support a 400K BTU heater.

You need to check with a gas tech if your pipe from the gas meter to the heater meets Pentairs specifications.

 

[JamesW]

That is your Aclara Gas Meter Transmission Unit (MTU).

BENEFITS OF A TWO-WAY FIXED NETWORK
Series 3500 MTUs operate on the high-performance Aclara RF Network system, transmitting hourly interval data over
individually FCC licensed 450 to 470 MHz radio frequencies without outside disruptive interference.

The high-performance MTU is FM certified, intrinsically safe device designed to be an exact match for a gas utility’s existing meter population.

The high-performance Aclara two-way network allows gas utilities to remotely update MTU firmware.

In addition, a signal from the utility can set off a synchronized read of all system MTUs, collecting the data needed to reconcile the amount of gas entering the system to the billable gas that is consumed.

 

[JamesW]

A "Gas Meter Transmission Unit" attached to a gas meter refers to a device, often called a "smart meter module" or "ERT (Encoder Receiver Transmitter)", which is added to a standard gas meter to enable automatic, wireless transmission of gas usage data to the utility company, eliminating the need for manual meter reading by a technician; essentially, it allows the meter to "communicate" its readings electronically.

You should have a meter somewhere.

 

[JamesW]

Exhaust Gas Temperature.​

While running, press and hold the On button to display the exhaust temperature (Older Models).

The new models use the Menu to get the SFS.

Here is what the normal exhaust temperature should be:

• Below 250 degrees...very low
• 250 to 290 ..................low
• 290 to 350.................acceptable
• 350 to 480 ..................high
• Above 480...................error/shutdown.

Note: HD models can be up to 75 degrees higher. HD models use a cupro nickel exchanger and the efficiency is slightly lower resulting in less heat transfer and more waste heat.

If the exhaust gas temperature is higher then normal then water may be bypassing the heat exchanger through a broken bypass valve.

If you hold down the "pool on" button, it stays on 80, then flashes to 40, then back to 80, then the 80/40 reading and E05 indicate that the board is not getting a reading from the sensor. It's usually a bad sensor or damaged wires.

 

[JamesW]

E05 means that the board is getting a reading of O.L (Open Line) from the sensor.

Open Line or (Over Limit) means that the resistance is infinite or over the limit of the meter.

O.L means that there is no continuity between the two test points.

E06 means that the board is getting a reading of 0 ohms from the sensor.

The sensor should read about 3.8 Megaohms, which is 3.8 million ohms at 77 degrees F.

 

[Ukiwis]

Thanks for the assistance ajw22 and JamesW.
I checked my neighbor's meter and they have the same setup. The tag that is painted over says "For So Cal Gas Co Use Only". I phoned the gas co and was told I have a large Size 4 Meter that supplies gas at 14.73 PSI. I do not know where the gas line is routed to get to the other side of the house where the pool equipment pad is. The distance may be more than 200 feet.

I have decided to replace the heater with the exact same model.