higher than \"normal\" system pressure.

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I have a oil fired hot water system . My cold pressure is about 18psi and goes up to about 20psi @ about 150 degrees and up to about 24 psi @190 degrees. I have tried shuting off the auto feed and then draining off the boiler until pressure goes to 0 degrees. I then open up the auto feed and the pressure goes back to where it was. I get plenty of heat . Is there any problem with this or shouldn't I worry about it? I live in a one story ranch home.

Mark Eatherton1

Sounds like

your expansion tank may be partially water logged.

Is your tank a round long cylinder mounted on the ceiling, or a fat squatty tank attached to the system piping?

If it IS a ceiling mounted tank, you need to COMPLETELY drain the tank (with the water shut off obviously). Then your pressures should stabalize.

ME

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pressure too high

> your expansion tank may be partially water

> logged.

>

> Is your tank a round long cylinder

> mounted on the ceiling, or a fat squatty tank

> attached to the system piping?

>

> If it IS a

> ceiling mounted tank, you need to COMPLETELY

> drain the tank (with the water shut off

> obviously). Then your pressures should

> stabalize.

>

> ME

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pressure too high

I have the new type expansion tank . The system was installed in sept.03. and was always this way.

Arthur

Boiler pressure

If your tank is not water logged then it sounds like your tank might be a bit on the small side. Water expands as it heats 1/22th of its total volumne cold to hot. If you can drop the pressure to say 15psi and leave it at that ok it may go up to say 20+ but no problem sleep easy.
Unless you have a 3 storey home 15psi should be ample. 1psi = 2.3 feet in vertical height so that 15 psi at the boiler will raise the water level to 15 x 2.3 ft = 34.5 ft. By the way the cold pressure in the boiler should = the tank pressure when the boiler is empty.
Good luck.

Mark Eatherton1

It may be OK...

it sounds as if two things are possibly happening. First off, 18 PSI is higher than normal. Normal starting pressures for a normal house is 12 PSI. Secondly, it sounds as if the tank may be somewhat undersized, or over pressured. With the boiler pressure at ZERO pressure, use a tire gauge and check the air pressure on your expansion tank. In your case, 12 PSI is perfect. Then, loosen the adjustment screw on the pressure reducing valve and turn the water back on. Slowly adjust the screw inwards until the gauge preads 12 PSI.

Now fire the boiler and see how it does. Technically speaking, you should always keep the operating pressure at least 10% away from the releif valves setting. If your relief valve releives at 30 psi, then 27 psi would be the max pressure you'd want to see duriing peak operation.

G'Luck

ME

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reducing system pressure

Thanks all for your suggestions. I really like the advice given by "ME" as this makes a lot of sense to me. I had a feeling that maybe my new water reducing value may be set wrong from the factory . Have any of you come accross this? I really enjoy "the Wall" as I'm a very techinal type person and love to learn.

DanHolohan

Is your circulator

on the return side of the boiler, and is the feed valve piped into the inlet side of the circulator? If so, the feed valve will feed once, on the first circulator start, and bring the system pressure to 18 psi. Then once your burner heats the water the pressure will rise above 18 psi because, at the higher fill pressure, the tank is effectively half the size it needs to be for the system volume.

Got photos?

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boiler pressure.

Dan First I'm impressed that you answered my post. I understand that "Your the Man"! Yes I do have the circulator on the return. Old fashioned way I learn now from the wall but hey I'm old fashioned (age 70 years). My feed comes in under the expansion tank a size 30. I'm running a V83 burnham . A "sweet" well made boiler I think. I'll try and include some pictures later for clarification .
Thanks again ,

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