Water Heater Bypass

[Dalwyn]

Just finished winterizing my unit doing the air pressure method. In the past I have always set the water heater bypass to the bypass position simply because during the purchase walk-through the mechanic said that was necessary. However, when reviewing the winterizing instructions in the manual, the only place I see it mentioned about setting the water heater bypass valve is in the section for additional winterizing by adding the anti-freeze to the lines. I add anti-freeze to all the traps and in the grey and black tanks, plus the macerator but not the lines. Is it necessary to set the water heater bypass valve to bypass when doing the air pressure method?

[Countryboy59]

I set to bypass, open water heater drain, and remove the plug. Then do air. I left plug out and drain open.

[Dalwyn]

Appreciate the reply.

I put plugs back in, so nothing unwanted manages to get in the openings.

After thinking about it, I am wondering why set the bypass. Once the tank is drained and the lines are blown dry what does it accomplish? Not that it is hard to do, but at 68 I'm not as agile as I used to be and the bypass valve is not that easy to reach.

[OTRA15]

Originally Posted by Dalwyn

Appreciate the reply.

I put plugs back in, so nothing unwanted manages to get in the openings.

After thinking about it, I am wondering why set the bypass. Once the tank is drained and the lines are blown dry what does it accomplish? Not that it is hard to do, but at 68 I'm not as agile as I used to be and the bypass valve is not that easy to reach.

Ditto. Many of us also avoid the use of antifreeze in the plumbing supply lines.

When using compressed air to blow out the lines, you can ignore the bypass valve IMO. We also let the air blow out the drain hole in the water heater, and replace the plastic plug loosely. No harm in opening the pressure relief valve at the top also, to dry out the piston and spring assembly, especially if your water is hard. Not necessary though.

Don't forget to remove the filter assembly from the water pump, and drain the lines before and after it. Depending on your model and layout, an additional precaution we take is to blow back into the line coming from the water tank [by mouth] in case a low point in that line contains any small amount of water which can freeze. Another nimble move!

Cheers,

Peter

PS -- Just realized you have an AI, but I assume the above also applies to your unit. Assuming you also open all the H/C low-point drains, if any, especially after doing all the compressed air work. Water can find its way down to the drains during all the other work.

[Dalwyn]

Originally Posted by OTRA15

No harm in opening the pressure relief valve at the top also, to dry out the piston and spring assembly, especially if your water is hard. Not necessary though.

Thanks, I had not thought about opening the pressure relief valve. Will do that. The two low drain points are back open. Manual says there are three on my unit, but I have never been able to find the one that is suppose to be under the sink. :-)

[ROBERT CROSS]

Originally Posted by Countryboy59

I set to bypass, open water heater drain, and remove the plug. Then do air. I left plug out and drain open.

Same here....'cept I just blow the tank & leave the brass valve open.

Bob

[OTRA15]

Originally Posted by Dalwyn

Thanks, I had not thought about opening the pressure relief valve. Will do that. The two low drain points are back open. Manual says there are three on my unit, but I have never been able to find the one that is suppose to be under the sink. :-)

Hopefully another AI owner will chime in, as I am not sure.

Good luck,

Peter

[CBWELL]

Water can sit in the line ABOVE the bypass valve. It is possible to freeze and break the bypass valve if this water is left in the line. Always open this valve when blowing out lines. Just my thoughts, after replacing the valve from freezing!!!

[OTRA15]

Originally Posted by CBWELL

Water can sit in the line ABOVE the bypass valve. It is possible to freeze and break the bypass valve if this water is left in the line. Always open this valve when blowing out lines. Just my thoughts, after replacing the valve from freezing!!!

Not sure that everyone has the same bypass valve operation in mind with the terms "open" and "closed" -- but if you are using air it should not matter IMO.

After first draining by gravity all the low point drains, and water heater drain plug, you close all the valves, and blow out all the lines with compressed air -- there should be no water left in the supply piping system to freeze IMO. You must use adequate air pressure [30 PSI or so] and open each and every hot and cold faucet individually, then go around again and repeat this process.

Then open all the low point drains once again, and close them, then repeat the faucet-by-faucet blow out with compressed air one more time.

This might take an hour or so, but the redundancy of going around the circle thrice [which some might call a waste of time] gives you some insurance that very little water remains in the supply piping.

After the above, no water should remain in the lines near the bypass valve IMO, whether it is "open" or "closed."

If the valve has caused the compressed air to bypass the water heater, you still have to deal with winterizing the water heater in some fashion.

Peter

[Rig Rat]

Originally Posted by Dalwyn

Thanks, I had not thought about opening the pressure relief valve. Will do that. The two low drain points are back open. Manual says there are three on my unit, but I have never been able to find the one that is suppose to be under the sink. :-)

When you take your drawer entirely out from under the sink you should see two valves near the water pump that look similar to the ones below.

There is a nice pictorial of the steps to the AI winterization process posted by jerhofer at;

http://www.airforums.com/forums/f240...te-109498.html.

Scroll down to his posting #13.

[Dalwyn]

Thanks for the picture. My water pump is not located under the sink, it is located on the fridge side. I do turn both of those valves.

[Titus]

When winterizing I empty the hot water tank, including blowing out the lines leading to it. I then close the bypass valve. There may be no benefit to closing the bypass after blowing out the lines, but I put about a gallon of pink stuff in the fresh water tank and turn on the pump to fill the pump with antifreeze. I don't think that blowing out the system (via the hose connection) gets the water trapped between the fresh water pickup tube and the first joint downstream of the pump.

As far as access to the bypass, I cut a U shaped piece out of the wooden panel just in front of the valve (the panel below the bench seat) and put a spring-loaded-closed hinge there. I can then flip down the U shaped panel for easy access to the bypass valve. The panel does not show much when the bench seat is being used - and about the only time our bench seat is not down for a bed is when we are home unpacking, cleaning, and repacking.