New home owner with heat problem

Brad White

That is certainly the first thing I would do. My caution is, I do not know your skill and confidence level. But to try that, grab a hose and a bucket and have at it. When you drain the tank, air will gurgle back in to restore the charge.

Once you get the charge back in place (and if this was the problem) you should be OK for a while.

BUT -and this is a big item- whatever caused your tank to fill with water and your air charge to be lost, should also be addressed.

Check to see where your expansion tank connects to the system. It probably, based on what I have seen for homes of that vintage, connects to the boiler itself or the outlet pipe from the boiler. The circulator (aka, "pump") is often at the inlet to the boiler, thus "pumping to" the expansion tank. This is wrong. Common, but wrong. The connection point of the expansion tank wants to be upstream of the circulator. Unless this is done, you will draw air into the system and for reasons too complicated to explain right here, lose your expansion tank cushion.

Juan

I just bought a home and just turned on the heat at the boiler. My system is about 50 years old and its base board heating. The problem is this,

I turned on the system and after about 20 mins I'm getting a gush of hot steaming water coming out of a relief valve close to the boiler it self. I read the card thats attached to it that basically says that water will come out of this valve when the pressure exceeds 30 lbs. But what started out as a drip turned out to be a large constant pressured gush of hot steaming water and other drips on various valves. The only way to stop this gush was to turn off the boiler.

How do I or can I rememdy this problem myself?
It seemed like this valve was doing its job but it appeared way beyond what it should do. Which led me to believe that maybe there was too much air in the system and not letting the heated water travel thru the system and it was just forcing it back out.

Was I suppose to bleed out the system before I turned on the system?

The thermostat was set at 69 and the boiler was turned off since last winter.

Any info would be greatly appreciated.

Jim Bennett

I'd recomend....

calling a heating service company.

This could be a potentially serious problem that you should not try to solve on your own.

Have a serviceman look over your system and explain it's operation to you.

Good luck,

Jim

Brad White

Jim is right

This is a time to call a service person to check it out.

For your information and consideration, some of the things I would expect would cause what you are experiencing:

1) Expansion tank is full of water. If it is an overhead tank between the basement joists (typical for a 50-year old system) it is likely full of water. If it is a newer bladder/diaphragm type tank, the membrane might be ruptured. Bottom line is the same- there is no place for the expanded water to go.

2) Fill valve may be leaking-by, allowing street pressure (or at least higher pressure than your relief valve setting and obviously higher than your expansion tank can absorb) into the system.

3) You may have an internal domestic hot water heating coil in the boiler. Even if not currently working, it may still be connected to the city water and have a pin-hole or greater leak. Again, more pressure in the system than you can stand.

4) Runaway control. If the water is that hot (180F or even 210!) and the boiler does not shut off, that would be more obvious to you. This is probably not the case. Pipe the relief vent to within six inches of the floor.

Of the above, I would say that #1 is most likely, given that it occurs only when the boiler has fired to temperature (as you said).


Bottom line though, get a pro to look at it if you are not confident of what is going on. What I mention above is for your better understanding of the system.

Congratulations on being a new homeowner! Stick around so once this is behind you, you can set about making the system the best it can be.

Juan

Brad....

If you think your first idea to my problem is that the tank is filled with water can I empty it out?

I found that tank that sort of resembles a muffler with a faucet at one end, can I just open it and drain it.

Before the tank theres another valve which I assume shuts off water going to the tank, of which is leaking (mentioned in my first post as to the one leaking), can I safely do this?

Juan

Brad....

Thanks alot for all the info!

I was able to complete the task and it resolved the problem. The heating system is working fine now. I just now have to address the 2 leaky shut off valves.

Glad I found this site. Thank you Very much!

Brad White

You are welcome, Juan

Just remember to keep monitoring the pressure until we figure what is causing this. It may have happened over years or it may happen every month, we just do not know.

As a preemptive strike and just because it can solve a number of issues, you may want to replace the tank with a pair of Amtrol type expansion tanks and move the connection point to the inlet side of the circulators while you are at it.

I say "a pair" of tanks because they are not much money and older systems tended to have more water volume. Plus, you get some redundancy.

Your cold fill pressure should be between 12 and 18 lbs. if you have a two or three story house, respectively. When hot, it should not gain more than 6 lbs. and certainly go nowhere near the 30 PSIG limit.

So, keep an eye on it and stick around here. I suspect you will be back...even to check in.

Best,

Brad

Billy_6

HOT WATER

Nobody has mentioned that the water coming out of the relief valve can be 180 degrees or more. This water can scald and permanently scar you in less than one second of contact.

If you are going to play with your heating system please be careful!