Flushing steam boiler frequency

bkselly

Recently moved into a house for the first time and learning about heating system. I have an oil-fired steam system and was told I need to get it serviced by oil company once a year which I did earlier in the month

I asked the guy what I should do in terms of maintenance and he said to flush the boiler once every 2 to 3 weeks. Other people on this forum are saying at most to flush once a year, and I am also hearing some distinction between flushing the whole boiler vs flushing the lower water cut off

Could you guys please explain or point me to a guide as to what I should be doing for regular maintenance? Attaching photos of the boiler for reference

Thanks

ethicalpaul

Don’t listen to that guy, that’s for sure

jhewings

The 2-3 week frequency generally is to "blow down" a "float" type LWCO. You do not have a "float" LWCO. You have a "probe" type LWCO which has a probe sticking inside the boiler to verify there is enough water to operate. It is not necessary to flush your boiler more than once per year. Your yearly maintenance contract should include the service guy pulling out the probe and checking/cleaning it or occasionally replace it. There actually in not anything you need to do if you get annual service, but it would be useful to learn how the boiler works and what the controls do. This could help you spot an issue later. There are some good books available at the store such as "We Got Steam Heat".

bkselly

@jhewings thanks a bunch - that was very helpful - I will get the book

SteamingatMohawk

If you go to HeatingHelp.com there is a Help Center with good information.

https://heatinghelp.com/systems-help-center/category/steam

bkselly

Hello all - sorry to resurrect an old thread but had another question on the topic.

jhewings mentioned that it is not necessary to flush the boiler more than once per year (since I don't have a float LWCO), and that if I get annual service, I don't need to do anything at all.

In the annual service summary, I see the technician had done "annual tune up and vac" as well as "cleaned end cone, electrodes, gauge glass" among other checks, but I don't see anything indicating flushing the boiler

Is there an expectation that the boiler is flushed during the annual service (hence why I don't need to perform any maintenance at all), or is it that the probe type LWCO setups don't need any flushing period? If the latter, what is the benefit of flushing once a year (as jhewings mentioned) vs not flushing at all?

I did get the "We Got Steam Heat" book, but I only saw flushing discussed in the float type LWCO context

ethicalpaul

In my opinion, you don't really want or need to flush the whole boiler ever. Every year, or two, or three, you want to clean the LWCO probe, and that will require you to drain the boiler down to the that level. That's as much draining as I would do—the more you drain, the more you fill, and the more you fill, the more rust you make in your water.

clammy

As for flushing or wanding the boiler out to remove mud that is usually not included in any oil burner service unless specified by the company doing the maintenance and usually this will increase the price of the service . I would say from my experience is that if your new to the home and really have no prior knowledge of the maintenance that has been performed to the system i would suggest that a water side cleaning of the boilers water passages and a flushing of wet returns if your system has wet returns . As some say this really is not necessary i see it as if you do not know if it been done then you should inquire. Not every company provides this or even have a clue as to why it might be necessary . As for yearly service removal of sight glass assembly including the valves not just the glass,removal and cleaning and or replacement of lwco probe ,removal and inspection of safety valve piping to ensure that the inlet piping is not blocked (common on steam boilers not maintained properly )Flushing of the boiler block and wet returns . Removal and clean of pressuretrol pigtail and connecting piping to the boiler , the addition of a low pressure gauge 0-3 psi should be installed aside from the 0-15 gauge that is code required . This gauge will let you know if the pressuretrol is set correctly and working properly . Pressuretrol should be tested to ensure it set correctly and operating as required

After that the low water cut off should be tested to ensure that the burner shuts off when the burner is operating. Of course if you do have the boilers water side cleaned make sure the boiler is fired after wards till its steaming to help drive out the dissolved oxygen in the fresh water help reduce fresh o2 from eating the cast iron to some degree .

Again some will say not to wash the boiler out but i have seen drastic results of removing mud in steam boilers in which by doing so has improved the quality of the steam the boiler produces and cut the time steam reaches the end of the mains due to it being dryer and being produced by clean water not producing steam by boiling mud laden water in the boiler . A clean boiler not loaded w mud certainly will increase performance and lower run times which reduces fuel use ,these are things most companies selling fuel don't concern them self w beng they make profit from the more fuel sold and used .

As a side note i would about 90 % if not more of the steam boilers in residential homes suffer from poor near boiler piping and zero proper piping to permit washing and wanding out of the bottom of the boiler or flushing of wet returns .There's more money to make replacing it every 12 to 15 years . Buy some of dans books and learn so your not a sheep and have some power, its called knowledge so u can sniff out the bull when it being served steaming hot as is usually the case .

peace and good luck clammy