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Refurbish or replace hydronic HB Smith/Roberts Gordon Powerpile

tbird6391 Member Posts: 9
edited February 2016 in Gas Heating
I'm impressed with the wealth of knowledge on this site, and looking to pick a few brains regarding our situation.

Ours is a 2600 Sq ft 2 story home with 3 zones built in 1958. The history of the system is well known. It has run reliably for nearly 60 years with what amounts to probably only a few hundred dollars in repairs.

The heating consists of the original HB Smith - Mills boiler tagged as no. 100-1100-150-1500. It is fitted with a Roberts Gordon atmospheric upshot burner with Powerpile gas valve. Originally there were 3 B&G circulators I had replaced 2 years ago with Tacos, as I didn't trust the motors on the B&Gs, which I did retain for possible rebuild. The system has manual flow valves that will let it gravity feed. It also gravity feeds an in direct water heater.

There are no leaks apparent as the fill valve is left off and pressure stays constant in between bleeding. I did get a lot of air out this year, presumably that which had entered when the pumps were replaced. There is a generous coating of white powder all over the combustion chamber. I have a pic of the inside, if needed I will try to upload.

The system was combustion tested a week or so ago and it is clean with 1 or 2% CO. When the tech opened it up we found one of the pieces of the ceramic diffuser has a radial crack. These are made in 2 sections, the Crack is in the lower one with the lap joint holding it together. So it's all there, it just looks like it might fall off. From what I see here and other places these diffuser parts have long since vanished from the market place. Being so old, I don't trust the gas valve or the regulator either.

I was hoping to recondition the burner or replace it with a similar one (ie Powerpile) as here in CT we are frequent victims of week long power outages. But the challenge seems to be finding the right tech to work with.

For example the first tech to come was here for nearly 2 hours trying to figure out how to power down the burner for the chimney sweep. Good thing he had his text book from school in the van and his brother on the phone.

The next tech was with a large hvac contractor. They quoted about 1/2 the price of a new boiler to replace the Roberts Gordon with a Carlin that is electric dependent. They said they don't want to do the repairs but will oblige. While I trust they could get this done, They seem to miss the point about the Powerpile. And to charge about 5x the cost of the burner to install it seems more than bit much.

I did find the Adams SPT economy burner is available with Powerpile. But email communication with them broke down when I asked them to quote all the parts necessary for the burner to arrive in a plug and play state.

So the dilemma is to decide whether to pursue reconditioning this system, or replace it. I love this system in that it will heat the house with no electricity. However its age and lack of safety features makes me a bit nervous. Ideally we would look into adding some safety features such as low water cutoff if that is even possible. However this puts me back to finding the right tech that is well versed in this type of work and "does the right thing".

I am not overly concerned with efficiency, an improvement would simply be a bonus. The gas bills here for the cold months for 2600 Sq ft are about 1/2 what we paid to heat 1800 Sq ft in the next town over with an oil burner installed in 2003. But that reference is from the winter when oil was over 4 bucks a gallon.

I am, however, concerned with reliability and safety, and our lackadaisical power company management team.

What are your professional Opinions on reconditioning/retrofitting the system vs replacement?

If replacement, what are the most bullet proof units out there?

What would you do in your own house, and why?

We will be using the original chimney, which needs a liner installed.
Energy Calc was not done, I will insist once we get to that point, but 140000 BTU was suggested based on Sq ft.

Any other info, pros and cons, potential safety issues, prior experiences, please share.

I am especially interested in hearing from experts servicing southwestern CT.

Thanks in advance.


  • kcopp
    kcopp Member Posts: 3,819
    What do you have for radiation? It is time to upgrade. A lot of changes have come along since '58
  • tbird6391
    tbird6391 Member Posts: 9
    The 1St and 2ND floor (zone 1 and 2) are cast iron units exactly like the one in the pic, but recessed into the walls. What's the trade name for these?

    Zone 3 (cellar) is copper baseboard. The boiler itself sustains the cellar near 60 degree range so this zone never comes on.

    Any thoughts on upgrade path / options?
  • deadmansghost
    deadmansghost Member Posts: 32
    tbird wrote , "The system was combustion tested a week or so ago and it is clean with 1 or 2% CO. When the tech opened it up we found one of the pieces of the ceramic diffuser has a radial crack."
    This is a red flag, usually see CO stated in PPM increments, you should get the tech back immediately to check this out and repair or adjust burner to lessen this reading.
  • tbird6391
    tbird6391 Member Posts: 9
    Sorry my bad it's ppm. Printout attached.
  • SWEI
    SWEI Member Posts: 7,356
    A steady state CO reading doesn't tell the whole story.
  • tbird6391
    tbird6391 Member Posts: 9
    Steady state vs...? what are the other tests needed. Tech had the probe in there for about 20-30 minutes.

    I'm looking to a) replace or recondition the burner and add modern safety features while retaining the powerpile
    Or b) find the most bulletproof replacement boiler.

    And shopping for a trustworthy tech servicing CT.
  • SWEI
    SWEI Member Posts: 7,356
    The way the CO readings change as the appliance passes from light-off through steady-state operation to shut-down provide a lot of information to a properly trained technician.
  • tbird6391
    tbird6391 Member Posts: 9
    Ok thanks. I'm guessing he did that without my realizing. I had to go turn up both thermostats while he was measuring to kick the burner on, and he left the probe in long enough for it to cycle back off. Don't what portion of the test the printout is showing. The guy did seem to know his stuff.