New water heater installed, causes furnace problems

[Doctor Arcane]

Right after we had a replacement gas hot water heater installed, our gas fired furnace began to leakand it seems to forced the water it circulates (and gunk) out of several joints even though it has not turned on in weeks. The furnace does have a defective automatic fill valve but tat caused no trouble last winter.

Whats happened? We're calling the plumber back, but I'd like to get other opinions.

thanks

-Mike

please respond here to arcane2501 -at- mail.com (my altavista acct doesnt work anymore)

[m Ransley]

Ck the pressure gauge on the furnace, what does it read? How many feet apx. from boilrer to top radiator. probably bad auto feed , overfilling and over pressurising the system, Is the gauge in the Red. turn off water and drain a little. What is you water pressure incomming.

[Speedy Jim]

Put a pressure gauge on the cold water line. Easiest way is to get a gauge with a garden hose connection, you can connect to the heater drain valve.

I'll bet a box of donuts that the pressure creeps up when the water heater fires up and no water is being used.

If I'm right, the heater needs to have a thermal expansion tank installed. You can read about how they work and why they are needed here:

Or, do a GOOGLE Advanced search:

on alt.home.repair for "expansion tank" Hundreds of hits.

Why didn't it happen with the old tank? Can't say from here, but something changed.

Jim

[Joseph Meehan]

I'm with Speedy on this one.

[m Ransley]

He said Furnace leaks well furnaces heat air boilers heat water in a basicly closed loop. He said Auto Fill valve , only Boilers have Auto Fill Valves not Furnaces. He has a boiler and separate water heater both separate and non interfering. The only way a boiler will leak is the plumber accidently bypassed the auto fill pressurising the system to line pressure or the Auto Fill vale is defective. Either way he must note the pressure gauge level and turn off the feed and drain it now.

Also He induced new Oxygen into the immediate boiler this must be cooked off now or the life will be shortened as it will rust over the summer. This should be done by mnfg . instructions to run time. Its summer , but it is necessary now.

Expansion tank? He is talking Boiler, it has one already. If his water pressure is high enough its New Boiler time.

Check feeds first If it was manualy done your Hack owes you possibly a new boiler

Dont let that Auto Fill valve go out of your possesion, Mark it and verify it in writing to any repair man if in fact it tests good, your hack screwed your system , maybe permanently

[m Ransley]

A 99.99% chance of major installer error.

[CBHVAC]

After reading it 3X, to make sure I read it right....I 3rdthat suggestion...

[Eli Siegel]

The plumber has come. Because the refill valve was defective, a surge of pressure hit the boiler when the water was turned on after the water heater was installed. Fortunately, damage is not major and the system would have to come down anyway to put in the new refill valve. Evidently, this is rare or else plumbers would always turn off the cold water to the boiler when they put in a new. separate water heater which they do not. E.S. , Dr. Arcane's father

[Eli Siegel]

The plumber has come. Because the refill valve was defective, a surge of pressure hit the boiler when the water was turned on after the water heater was installed. Fortunately, damage is not major and the system would have to come down anyway to put in the new refill valve. Evidently, this is rare or else plumbers would always turn off the cold water to the boiler when they put in a new. separate water heater which they do not. E.S. , Dr. Arcane's father

[m Ransley]

Pressure creep ? Plumber error. I hope he didnt exceed a safe limit.