Stinky egg smell from washing machine and dishwasher.

[serpent28]

Hello. I have unusual problem now for 4 years. The water that is in the supply hose stinks or rots I don't know. It's not the drain problem, the washer smells nice, it only stinks when it pours out the water that stays in the hose then the water is normal, but if the WM/DW is off for 4 hours it already gets the stink again if you start it and it starts to pour water into machine. Searched whole internet literally did not find anything like this. I tried to unscrew the 3/4 hose on the supply line with ball valve and it doesnt stink from that place, but if you unscrew it from machine side it starts to stink , its literally like half of the hose has rotten water and the other end (the supply end) doesnt smell.. Since i searched everything I tried AI chatgpt and claude.ai both suggested to try installing check valve but the question is where. On the ball valve or on directly on the WM/DW? It said that I can do both just to make sure that there is not backflow into main water line (because if the ball valve is open then the faucet which is on the same setup also starts to stink like eggs but not that strongly so obviously if ball valve is open it starts to collect the gases/water from the hose.

Here are Key Observations from the AI:

1. The smell occurs in inlet hoses, not drains
2. The smell is present only when valves to appliances are open (ignore this one since it doesnt make sense or it didnt understood what i said)
3. The same main pipe doesn't cause smells in the bathroom
4. The smell transfers to the faucet when appliance valves are open, when it's closed the faucet won't smell then
5. Both appliances are affected, suggesting a common cause
6. The smell is concentrated on the machine-side of the hoses

I asked further questions like remaking the setup since I use tee valve with 3/4 connector for appliences and I just added the same one on top of another to make 2 3/4 outputs since the WM/DW is in the same room. Here is the answer from AI

You should KEEP your ball valves! Here's why:

• Ball valves are for manual control (maintenance, emergencies)
• Check valves are for automatic backflow prevention
• They serve different purposes and work together well

How they work together:

1. Ball valve OPEN, appliance running:
   • Water flows normally through both valves
   • Check valve stays open due to water pressure
2. Ball valve OPEN, appliance off:
   • Check valve automatically closes
   • Prevents water from sitting stagnant or flowing back
3. Ball valve CLOSED:
   • No water flows at all
   • Necessary for maintenance or emergencies

The ball valve is still essential for:

• Emergency shutoffs
• Maintenance work
• Appliance replacement
• Leak prevention

So to be crystal clear: Don't remove your ball valves! The check valve would be installed AFTER the ball valve but BEFORE the supply hose. This gives you both manual control AND automatic backflow prevention.

So this is the claude.ai, chatgpt said to try adding check valve on ball valves first if the smell persists add another check valve literally directly to the washing machine or dishwasher.
Can somebody help me with this? Sorry for long post I wanted to include all the details since its been 4 years now.. The way I dealt atleast with washing machine was just run a rinse cycle so it pours the smelly water from the hose and then drain it and then put the clothes in. Does chatgpt make sense, can I install check valve directly on the machine and check valve after the ball valve? Will this keep maybe stronger pressure in the hose and prevent gases/air? And also if anything comes back into the hose from the machine the check valve could prevent it? In the whole setup I would need 2 check valves 1 on washing machine and 1 after ball valve and attach the hose then on the check valve. And do the same steps for diswasher since it smells too(diswasher is only 3 months old so its 99% not appliences fault. Also last time I tried to fix it was just replacing the hose, it removed the smell temporally only for 2-3 months and the smelly egg water which is present only in the first 1-3 mins of drawing the water into the machine came back again, tried to replace the hose again, same kinda result smell is gone for 1 month and it comes back again.. So I wonder if AI's suggestion to install check valve maybe help at least after the ball valve connection if I accidentally leave the ball valve open so it wont go into the faucet. Any help would be great, Couldnt find any information about this anywhere. The only answer I could find for this is insttalling water filter but they cost a lot and I dont want to spend that much money since the same water line is present in bathroom and there shower/2 faucets/toilet does not have this egg smell, the same pipe goes into the kitchen and there only the hoses smell if the ball valves are closed.

Edit: I added a image of what tee valve i use to connect everything. I have cold water pipe going from the bathroom to the kitchen it has 1/2 male end, this tee valve has 1/2 female connector which i put on the main pipe and as you can see it has 3/4 connector for machine and on the top it has 1/2 male connector, so I take 2 of those and join them together so I can connect 2 appliences, the top which is left the 1/2 male is connected to faucet. Kinda unusual setup but I had a plumber installing this I did not make it up myself.

 

[JohnD]

Please show us a photo of the route the drain hose takes, all the way from the appliance to the drain. Include other pipework connected.

Resident deposits of soap and fabsoft can accumulate within the machine, forming a sludge that bacteria eat which causes the smell of decay.

This can be removed using a hot hot hot washing cycle, with no soap, no detergent, no fabsoft, and a cup of washing soda crystals (sodium carbonate) often sold alongside laundry products. I do not know what it is called in your country. It is not the same as the soda used in cooking. You can put some white cotton towels in, because they will not fade or be damaged by the heat, and they will come out whiter, softer and cleaner than they went it. You may find this hard to believe but it is true. Observe the washing cycle, you will see that the water goes grey and foams up, even though you added no soap. This is due to the old soap residue dissolving. It may take several cycles to get it all out.

Cold washes, and adding products in greater quantities than recommended, will make sludge deposits worse. Once clean you can probably keep it under control with a weekly hot cotton wash with washing soda but no soap or fabsoft.

 

[serpent28]

I dont think you have read what I said, the smell comes not from the drain but from the inlet hose. The machine is clean, the drain hoses literally smells like soap (I detached them to check the smell), the filter on the bottom also does not smell. Its a problem with a intake water not the drain system, it literally has nothing to do with drain system. As I already typed the smell comes from inlet hoses, I don't think I need to repeat everything I wrote in the original post

 

[JohnD]

Yes, I know what you said.

If you think that you already know the answer, and don't want advice from anyone experienced with the problem, then I can't help you.

Goodbye.

 

[foxhole]

Yes, I know what you said.

If you think that you already know the answer, and don't want advice from anyone experienced with the problem, then I can't help you.

Goodbye.

Think it’s a yank , hence the problem.

 

[jj4091]

Are you on a mains supply for your water. Are any neighbours having the same problem. Have you tried disconnecting and capping the hoses for a few hours then draining them into a bucket and see if you have the same smell. Sounds more like you are having problems with a contaminated water supply than a machine problem.

 

[securespark]

I can only think that there may be an issue with a tank-fed supply where an animal has got into the tank and expired.

 

[robinbanks]

Have you replaced the inlet hoses with new ones made of a different material?

 

[serpent28]

Please show us a photo of the route the drain hose takes, all the way from the appliance to the drain. Include other pipework connected.

Resident deposits of soap and fabsoft can accumulate within the machine, forming a sludge that bacteria eat which causes the smell of decay.

This can be removed using a hot hot hot washing cycle, with no soap, no detergent, no fabsoft, and a cup of washing soda crystals (sodium carbonate) often sold alongside laundry products. I do not know what it is called in your country. It is not the same as the soda used in cooking. You can put some white cotton towels in, because they will not fade or be damaged by the heat, and they will come out whiter, softer and cleaner than they went it. You may find this hard to believe but it is true. Observe the washing cycle, you will see that the water goes grey and foams up, even though you added no soap. This is due to the old soap residue dissolving. It may take several cycles to get it all out.

Cold washes, and adding products in greater quantities than recommended, will make sludge deposits worse. Once clean you can probably keep it under control with a weekly hot cotton wash with washing soda but no soap or fabsoft.

Yes, I know what you said.

If you think that you already know the answer, and don't want advice from anyone experienced with the problem, then I can't help you.

Goodbye.

Sorry if that came in rude way. Since its been a long year issue we already checked the drains, everything is alright, everything is installed correctly, the washer itself smells nice and soapy there is no mold nothing, you can start a spin cycle where it draws the water there is no smell, hoses were unplugged to check for smell but everything is clean and smells nice and soapy. As I wrote the issue is the intake water it only smells when it starts to draw the water, replacing that intake hose fixes the problem for a month or two but it comes back thats why I wrote about it and there is no reason to look into this again since as I said everything with drain system was checked. We also have a program on the machine where you can select to wash it with a specific cleaning powder designed for washing machines at 90c, also we often use 90c function, the lowest temperature I wash is mostly 40c, and we avoid using too much powder, the machine is always left open to ventilate, and is cleaned with dry towel where rubber part is since its a common place for nasty stuff to build up.

 

[serpent28]

Have you replaced the inlet hoses with new ones made of a different material?

Yeah I tried 2 different ones but they are also cheap like 3-5 dollars for 2 meters. Can't find anything else here more expensive, also these are common hoses and mostly many people use them without issues so i dont know. I will try to order stainless steel braided hoses from amazon or some other place

 

[serpent28]

Think it’s a yank , hence the problem.

Sorry but what does that mean? lol

 

[Wayners]

Probably washing machine.

Look up cleaning cycle in the instructions manual.
On ours we have to hold down two buttons. Will do a hot wash killing the bacteria.
Chuck two bottles of white vinegar in and run cleaning cycle.
Start using powder and calgon.
Liquid tabs are terrible and cause sludge.
If you still get trouble it could be pump starting to struggle which is an easy swap and cheap.
Probably get error code for that though so wait and see.

Clean
Use powder and calgon
Problem should go away

 

[serpent28]

Are you on a mains supply for your water. Are any neighbours having the same problem. Have you tried disconnecting and capping the hoses for a few hours then draining them into a bucket and see if you have the same smell. Sounds more like you are having problems with a contaminated water supply than a machine problem.

The water supply comes from city lines into this building and all apartments. Haven't heard anything but I also never asked them I dont even know how to approach them with such issue lol. Since I was living here for atleast 13 years this never happened before but for some reason it started to smell from the machines, not from faucets,toilet,shower nor kitchen faucet and they all share the same cold water pipe, when I tried to unscrew the 3/4 connector from the pipe the water there doesnt smell at all, it is literally on the machines side, when you detach it from machine side then it stinks. No I never tried the experiment with the hose, I guess I can try it but doesnt align with the logic that the faucet doesnt smell when the faucet water literally comes from the tee valve where the machines are attached, but of course if the ball valve is closed to the machine then it doesnt smell if I open the ball valve and forget to close it the smell creeps up to the faucet too but when you closed it instantly stops after running for 10 or more seconds.

 

[serpent28]

So how about the experiment with check valve? at least to install it on the tee valve in case if its open the water from smelly hoses will not backflow into the faucet pipe/hose, and one on washing machine? Never heard of this method just thinking what AI suggested, if its washers fault it says that check valve on machine wont let any water or gas to go back into the hose and make the water smelly when sitting and check valve on tee valve in case if valve is open and nothing goes back to the main line from the washers. By the way I probably buy a new washer but I don't think that it will solve the problem because we had old dishwasher and had the same problem with same smell in washer and dishwasher and when we bought new dishwasher it didn't smell for 3-4 months and the same smelly rotten egg "infected" the new dishwasher too.. lol
So Check valve+new more expensive inlet hoses how does that sound?

 

[jj4091]

Can you disconnect the machines one at a time to see if it peculiar to the washing machine or the dishwasher. If it only happens after they have been stood for several hours then I'm not sure what good fitting check (non return) valves would have as the water in the hoses will be under pressure from the supply.