Water on the floor

Jldamico

I've been in my house almost 20 years. Except for extreme cold snaps, I've gone through 100 gallons /oil/month. Lately, I've been burning faster. No other changes, construction, etc. On Jan 11, I noticed water around the boiler. Found a leak in an external line and fixed it along with relief valve, feed valve, and feed shutoff. Floor gas been dry. Yesterday, I noticed water again and I'm down to an eighth of a tank of oil. We had 200 gallons delivered on the 11th. I should have been good until 3/11ish. We had unseasonably warm weather early in the week. I thought maybe a thaw and seepage. I vacuumed the water and it's returning. My question... If the boiler had an internal leak, wouldn't the water on the floor be hot or at least warm? It's cold. Any ideas?

Steamhead

Is this a steam or hot-water system?

EBEBRATT-Ed

Sounds like a boiler leak. When the boiler is running and hot the water may be evaporating off the boiler. When it is idle and a little cooler the water shows on the floor.

Probably time to pull the boiler jacket back and take a look.

You can probably make it until summer.

If the boiler is hot water the leak probably does not explain the high fuel consumption.

A steam leak above the water line would cause high fuel consumption

Is your oil tank indoors or outdoors?

Is your oil line visible or buried? One pipe or two pipe oil?

Jldamico

Tankless, oil fired dunkirk boiler feeding hot water baseboard heat.

Jldamico

And providing house hot water... Washing machine, dishwasher, sinks, etc.

Jldamico

The oil tank is inside. The line runs along the floor. My thought is that water leaks from the boiler, cold water comes in from feed to replace what's leaks out, the boiler needs to run more often to keep heating the new water coming in.

EBEBRATT-Ed

I can't see a leak in a hot water boiler affecting fuel consumption that much.

OIL TANK, indoors ? outdoors?

Oil lines visable or buried? one oil line or two?

I would shut the water feed off to the boiler and keep an eye on the boiler pressure. The pressure will vary as the boiler heats and cools but will eventually drop pressure if the boiler is leaking and you have the Make-up water valved off.

Do this on a weekend or some time when you are around to keep an eye on things

Jldamico

The oil tank is indoors. In the basement 10 feet from. The line is visible. Runs along the floor. One line.

Shutting feed... Wouldn't I have to make sure no one used water? To know the loss is from leak and not usage?

SuperTech

You can shut the feed for the boiler water, not the domestic tankless coil. They are separate. The boiler feed probably has a pressure reducing valve on it and a ball valve or gate valve before that to isolate the the boiler from the cold water supply.

You need a new boiler. Good news is now you can ditch the lousy tankless setup and get an indirect tank and higher efficiency boiler, then fuel consumption will be much less of a problem. 😉