I recently had a home inspection performed on a my potential first home.

The inspector made note of a problem with the tank-less hot hot water system incorporated into the boiler. I got a good look at the system with the inspector, and I am almost certain it is an HB Smith Series 8.
http://www.smithboiler.com/html/series8.asp

The problem he noted, was that the shower temperature started at 128oF, but then dropped to 86oF in 6 minutes with full hot water running. He said he was familiar with this problem, and that it was caused by corrosion in the tank-less coil impairing the heat conduction. He recommended repairing the boiler, or adding an indirect water heating system.

Since then, I have found replacement coils online for a few hundred dollars, would this replacement be a DIY job? It looks reasonably straightforward, despite HB Smith's recommendation of having a pro do it. Basically, the tank-less coil is inserted into a big hole in the boiler's water chamber. I assume the boiler would have to be drained and the coils swapped. Anyone have experience swapping the coils?

Lastly, what am I looking at cost-wise to have an indirect system installed? I see prices on the tanks alone near $1000. I'm trying to work this cost into the P&S agreement for the house. I know I may need a contractor's estimate for the work for the P&S negotiations.

Thanks in advance

Regards,

-Jim

 

Replacing a tankless coil can be any easy DIY job BUT it can turn into a nightmare for a seasoned pro. I've done them in less than an hour & I've had them take the better part of a day. Worst case: The boiler could crack resulting in the need to replace it.
Indirect is certainly the way to go but I doubt the seller will go for it. They will want to put in a separate electric or gas water heater.

 

I would find out the cost to have the coil replaced, have the seller deduct it from the sale price, and put it towards having an indirect installed the day you close

 

I wouldn't want to be fiddling with the boiler this time of year if there is a risk of being without heat for more than a day. If I cracked the cast iron, it would definitely turn into a pro job. It sounds like indirect will be the way to go long term anyways, to avoid having the boiler keeping the system up at operating temp 24/7. The more I read, the more it seems this type of tank-less is a cheap way out for the builder.

I think I'll get a quote for a pro to replace the coil, then work that price into the sales agreement. The savings will probably go towards an indirect system. The current owner is closing on a condo, I don't think they will want to mess around with fixing it and rather they will cough up the money.

Thanks for the help.


-Jim

 

Make sure a tempering valve is installed at the same time.

 

Well, I ended up buying the house and moved in this weekend.

Before the sale, we brought up the hot water problem, and instead of deducting the repair cost, the seller had a tech come and diagnose the problem. He came to the conclusion that the tempering valve was bad and replaced it. I have a copy of the receipt for $90 parts and labor. I assumed this meant the problem was fixed, but after taking a lukewarm shower this morning, I realised I was wrong.

I am a bit irritated for not following up and proving the system was fixed myself, and that I missed my opportunity to have the seller fix the problem. Either the seller and tech were trying to pull one over on me, or he was incompetent.

I don't want to replace the tankless coil, or do any major work on the boiler until spring. A guy at work has the same system with flow restrictor to keep the temperature up, and recommended I turn the boiler temperature up to 200 (high) to heat the hot water faster. Any other tips to improve the performance of this tankless system until it can be repaired or upgraded?

Thanks again,

-Jim

 

Be VERY careful when kicking up the boiler temp. Should the tempering valve fail, you could get scalded quickly. Before doing the flow restrictor & boiler temp part, make sure the tempering valve is set right.