How complex is it to replace boiler expension tank

[Margee]

My propane boiler needs its expansion tank replaced. The current tank is an AMTROL EXTROL model 30. Since it appears to be a simple one point connection and the cost of a new tank is less than $30 and my heating service company wants $327 to fix this problem, I am curious whether this is something a homeowner can safely repair. Are there any tricks to doing this that I should know about?

[SeattlePioneer]

If the expansion tank has a valve above it to isolate it while you replace it, it should be easy.

[Margee]

Good point. There are three pipes that go to the expansion tank. One appears to be from the the water heater tank (there is a stop **** valve on that pipe. The second appears to go up to the boiler (there is a valve on that line too). The third goes to a red zone valve (it's the same type of zone valve as for the three heating zones) and there is another stop **** valve past the zone valve.
The whole glycol solution needs to be drained, flushed and refilled so I figure everything should be done at the same time. Is there a "dummies" book for HVAC?

[SeattlePioneer]

Is there a "dummies" book for HVAC?

Not to my knowledge. It's not usually a job for dummies.

[NJ Trooper]

The whole glycol solution needs to be drained, flushed and refilled

Who told you that? Did they say why?

How do you know that the tank is actually BAD... that it won't be fixed up with a proper shot of air?

Is there a valve between the expansion tank and the rest of the piping? In other words, can you isolate the expansion tank from the rest of the system?

[NJ Trooper]

Unfortunately, when repairs need to be made on boiler systems, they usually need to be made NOW. One doesn't have the option of doing this at leisure and learning as they go. It's pretty easy to get yourself into a situation that you don't know how to get yourself out of easily, and it often happens that the pro's need to be called in anyway... and costs even more money.

I think you should be able to find someone to replace that tank (if it really needs replacing) for a heckuva lot cheaper than that! Shop around...

[sidny]

The glycol solution will last quite a while, however the inhibers do not, but inhibiters are available at just about all plumbing supply houses. Some are available in liquid form, and also test strips are alvailable. They will tell you if you have enough glycol to prevent freezing. Follow the directions on the label as how much to put in. I check about every five years.
I use a "little giant" pump to pump it in.You can pump it through your boiler drain or any other hose bib on the boiler side of your system. You can search this site for threads on boiler antifreeze, or go to the library, or Google this question.and you might find something on You tube. If you have a fairly modern expansion tank, looks like a barbaque propane tank colored grey, it will have a schrader valve [like a tire valve] on the top or bottom, and you can pump some air into it just to make a little coushon, you may have to drain a little water out [about a quart] out to make a little room. As the mods said this is better done in the warm weather.
Study up on this job. Always work safely.
Sid

[drooplug]

Why do you need to have antifreeze in your system?