Mineral Deposits on Flue Pipe from heating system

[maxfisherplayers]

Looking to buy a house and the inspection found an issue with the heating system. I have schedule an HVAC contractor to come out next week but wondering the severity and cost of the issue. The heating system is gas and is 15 years old.

There are white mineral deposits on the flue pipe and under the draft fan. The white deposits are a sign of poor drafting. The deposits are what is left after the condensation from when the flue gasses evaporates.
The flue pipe empties into the chimney.

Will an HVAC contractor need to go into the chimney to fix? Does this sound like a serious issue? What about a rough estimate that this would cost?

[Hube]

There are many variables to this problem.
it could be rectified simply by just adding some "makeup" air into the home because it is under a negative pressure .Negative pressure can cause draft problems to any flue/chimney.
Sometimes adding a foot or so to make the chimney stack higher will do the trick. either one of these remedies should be of no great expense.after all how do you put a price on you and your family's safety.
Get the Hvac pro to give you a cost estimate first before doing any work,and above all get a couple of more estimated from othe hvac pros.
then you will know where you stand as to any pricing issue.

[kactuskid]

Like Hube mentioned there are a ton of variables but I'd like to suggest some things you may want to consider. Most gas forced air furnace's have a lifetime of approx 15 years though you may get a few years more out of it if it was maintained properly. If the chimney is masonary and/or an outside chimeny and if the furnace is the only thing drafting up it you may need a chimney liner installed in order to get the proper draft. Most aluminum liners cost around $600.00 installed. Here's a link to explain about them and the reasons they're installed.
http://johnmills.net/liner/liner.html

A furnace that drafts up the chimney like yours is considered a mid efficiency furnace thus 80% effiecient. If and when you decide to replace your furnace, any new 80% furnace MUST have a liner installed in the chimney. Or better yet install a 90% effiecient furnace that does not utilize a chimney and drafts out the side of your house. But, if you install one of these and the water heater is still drafting up the chimney then you'll also need a liner installed. Or you abandon the chimney all together and install a power vented water heater, though they cost double a conventional type heater and require a 120 vac receptacle to power the blower (and the blowers are pretty noisy).

So, as you can see you're looking at spending some money soon to replace your furnace as it should of been written up by the inspector as nearing the end of it's useful life. You're also looking at installing a chimney liner or buying a new water heater . Prices on furnaces vary greatly between contractors, but at minimum you're looking at spending between $1800.00 and $2,500.00 for your furnace and another $400-$600 for the liner or water heater. Get some estimates of how much these items will cost locally and negotiate with the seller.

[maxfisherplayers]

Your replies are very helpful. I have an HVAC pro coming by to take a look early this week.

[wayneferr]

It sounds like at the very least you will need a chimney liner to prevent the acids ( the minerals you are referring too ) from forming on the flue pipe. This is a result of condensation forming within the chimney because the chimney is not getting hot enough to stay dry. What concerns me more is the condition of the heat exchanger due to the fact that there are acids forming on the flue pipe. Bad heat exchangers can lead to carbon monoixde posioning if properly maintained. I would have a certified HVAC company come out and inspect it so you know what kind of problem you may be inheriting. Do not rely on the home inspector for this particular project unless he is certified in HVAC. Best of luck to you !!

Originally Posted by maxfisherplayers

Looking to buy a house and the inspection found an issue with the heating system. I have schedule an HVAC contractor to come out next week but wondering the severity and cost of the issue. The heating system is gas and is 15 years old.

There are white mineral deposits on the flue pipe and under the draft fan. The white deposits are a sign of poor drafting. The deposits are what is left after the condensation from when the flue gasses evaporates.
The flue pipe empties into the chimney.

Will an HVAC contractor need to go into the chimney to fix? Does this sound like a serious issue? What about a rough estimate that this would cost?