Spa Gas smell when using air blower

[Mm824]

Hello!
We have an inground pool with attached spa. My daughter was just in the pool and went to turn the bubbles on, and it immediately smelled like rotten eggs/gas. I had her turn it off but am concerned of any additional gas leaking. I contacted our pool company, but they haven't responded back. Hoping someone might have an idea of the culprit!

 

[JamesW]

Do you smell gas by your blower?

Do you have a picture of the system?

Is the pool filled from a well?

How often do you use the blower?

How long does it take from the time the blower comes on until bubbles come out?

 

[Mm824]

I smelled gas by/in the spa not by the heater - almost like it was in the bubbles - but the spa is very close to the heater.

I ran inside to turn it off, and by the time I got back the smell was quickly dissipating and I did not smell anything by the heater.

The pool is filled from public water.

We don't use the blower often, probably haven't used it in a month.

The bubbles come out immediately and seems to otherwise work fine.

My daughter seems ok, and just said it smelled bad which prompted me to come over. Can the gas hurt her in any way? (Very distraught Mom here)

Thank you very much for your reply!

 

[JamesW]

Possibly bacteria creating hydrogen sulfide in the stagnant water in the line.

Maybe a gas leak near the heater and the air blower is pulling in some of the gas.

You can have an HVAC or gas plumber check for gas leaks with a sniffer device that can find gas leaks if you think that there might be a gas leak somewhere on the gas line.

If no gas leak can be found, maybe investigate the plumbing to see if it seems dirty or maybe a biofilm is developing in the line.

 

[JamesW]

Do you ever use dry acid, non-chlorine oxidizer or any products that contain sulfate?

High sulfates can be reduced to sulfide by bacteria and produce hydrogen sulfide.

Does the city water ever smell like hydrogen sulfide?

When the heater is on, does the exhaust have a noticeable smell?

 

[Mm824]

No, the city water is generally good and goes through a filtration system. We have never used any of the sulfates you mention and I've never noticed this smell before in any water at any point. We check our chlorine/chemical levels almost daily.

I just went back and turned the unit on. The smell is VERY distinctly and immediately coming from the pump/heater area. I did not smell anything near the first time I turned it back on. Maybe it was sucked back into the water somehow, or crept over to the pool area the first go round?

I shut it off, waited 10 minutes, turned it back on, and smell a faint smell of it now in the water, but not nearly as strong as before and it seems to go away quickly.

I seems like it's something to do with the heater and the air jets running at the same time ....

 

[JJ_Tex]

Do you have the smell when running the heater only (no blower)?

 

[JamesW]

Maybe have your HVAC or qualified gas contractor come out to check the heater and the gas supply to see if the gas line is leaking or the heater is malfunctioning.

Sometimes a gas pressure issue can cause a bad smell.

 

[Mm824]

No, not that I can tell, unless it's very faint that I can't detect that's being pushed around by the air blower.

 

[Mm824]

I think the blower is on top of tubing that I think only has a way valve that is connected to the spa plumbing. It's a straight pipe that goes underground I think.

 

[Mm824]

Maybe have your HVAC or qualified gas contractor come out to check the heater and the gas supply to see if the gas line is leaking or the heater is malfunctioning.

Sometimes a gas pressure issue can cause a bad smell.

Interesting. Could it be some kind of incomplete burn?

 

[JamesW]

Interesting. Could it be some kind of incomplete burn?

Possibly.

Hard to tell with the limited information available.

I would start by having a HVAC or qualified gas contractor come out to check the heater and the gas supply to see if the gas line is leaking or the heater is malfunctioning.

You can also begin to inspect the blower line for any signs of biofilm, but that can be difficult to tell.

If the heater and gas line are ok and the smell continues only when the blower is on, maybe do a line flush with a biofilm cleaner.

 

[Mm824]

Ok. That sounds reasonable.

Should I be concerned about swimming in the pool as is? Or my child having been in the water?

 

[JamesW]

At this point, we don't have enough information to tell exactly what is going on.

All we know is that there is an unusual smell.

 

[Mm824]

When I turn on only the heater, there is no smell.
When I turn on only the air blower, there is a faint smell in the water that dissipates.
When I turn on both the air blower and the heater, there is a smell coming from somewhere between the air blower and the heater.
There is also smell coming from the water.

If I take the water itself out, it is crystal clear and does not smell, not sure if that matters.

Sorry I am a bit ignorant here; trying to understand this as well.

 

[JamesW]

Do you have a picture of the system?

 

[JamesW]

The blower might be overheating and possibly burning inside.

Do you feel comfortable taking the blower off of the pipe and looking inside the hole that connects to the pipe?

How old is everything?

 

[Mm824]

I do, here you go:

 

[Mm824]

The pool was installed in 2005; the heater was replaced in 2015? I think?, and the grids were replaced last year. I can try take the blower pipe off this evening -

 

[JamesW]

Ok, I don't see anything that is an obvious problem.

The heater is surrounded by too much debris and it needs to be cleared out.

I would have the area checked for gas leaks and I would have the heater checked for proper operation.

Shut off the blower at the breaker and take it off of the pipe and look and smell inside for any signs of overheating or burning.

Don't do anything unless you are 100% sure that you can do it safely.