Time for cleaning of HTP modcon

Suzook

So its year 3, and based on my water here, i need to flush the HX on my modcon boiler.. Im getting different opinions on what to use. Seems like White vinegar should do the job. Run it though it for an hour, or 2. Thoughts? Thanks

EdTheHeaterMan

Look in the installation and operation manual that came with the unit. it may say something like this:

C. Cleaning Water Side of Heat Exchanger
1. Make sure power is
turned off to the boiler.
Run water through the
hot water system to
ensure it is below room
temperature.
2. Close isolation valves
on the return and supply
connections to the
boilers as shown in the
piping diagrams in this
manual. Slowly open the
ball valves and release
pressure into a bucket.
Once pressure is released,
connect a hose to the
water line to flush the
boiler. Scale removing
solution may be used, but
must be approved for use
with stainless steel and
FDA approved for use in a
potable water system.
3. Thoroughly flush the
heat exchanger before
commissioning the unit
back in service.

Vinegar is an acceptable solution, there are also commercially available products specifically designed for this procedure. I carried 1gallon bottles of vinegar on my service truck so I could flush a system if a customer requested it while I was there for something else. You know... "since you are already here, how much to service the water heater?" I would be prepared to say "Yes, it will cost $$$"

But usually, I would bring the commercially available chemical if the job was scheduled to be Maintained and it included a Flush.

The vinegar was also on the truck for those small oil spills made during a service call, when the customer was especially sensitive to the oil odor. I would tell them that vinegar would help cut the oil odor. (Then add... If I had a clove of garlic, I could make it smell like a Cesar Salad) ...True story.... I always liked to add those extra little tidbits for the customers amusement... Like ..."I hate to heat and run... but other customers are cold!"

Suzook

Thats EXACTLY what it says, so im guessing vinegar should do the trick, without harm. Thanks

Ironman

 What model HTP?
 Why do you think that you need to flush a closed loop system after 3 years? Or, is this a combi and you’re referring to the domestic side?

Suzook

Ironman said:

 What model HTP?
 Why do you think that you need to flush a closed loop system after 3 years? Or, is this a combi and you’re referring to the domestic side?

It a htp uft-80, it calls for flushing the hx. Based on my water here, I should do it every 3 to 4 years. But now that I'm looking, I don't have a way to isolate the hw side with a shutoff valve. Gonna have to sweat one in. Ugh

There's an old pic

EdTheHeaterMan

A work of ART.

I'm talking about the brownish wall with the white artwork on it.

I think the drywall taper was named Art

Ironman

Well, the I/O manual actually says once a year, but that’s hogwash. The only way that the heat exchanger can have a scale buildup would be if there are leaks on the system which are causing fresh water with fresh minerals to be added regularly. As long as there are no leaks, there are minerals being added to require de-scaling.

Suzook

EdTheHeaterMan said:

A work of ART.

I'm talking about the brownish wall with the white artwork on it.

I think the drywall taper was named Art

Lol, it's in my garage. I sorta thought about properly taping it and paint, but it would then be better than the rest of the garage.

SuperTech

The way that expansion tank is installed would make me nervous. If that tank fails and becomes waterlogged its going to put a lot of weight on the piping. I'd support it with some threaded rods and kindorff....but then again that is an old picture. 

Suzook

Ironman said:

Well, the I/O manual actually says once a year, but that’s hogwash. The only way that the heat exchanger can have a scale buildup would be if there are leaks on the system which are causing fresh water with fresh minerals to be added regularly. As long as there are no leaks, there are minerals being added to require de-scaling.

Manual actually says 2 to 3 years for my water levels here where I live. I believe I have no leaks, but with copper buried in slab, it's a possibility. I figured for an hour of my time, why not do it?

Suzook

SuperTech said:

The way that expansion tank is installed would make me nervous. If that tank fails and becomes waterlogged its going to put a lot of weight on the piping. I'd support it with some threaded rods and kindorff....but then again that is an old picture. 

Yes, old pic during install, I should have noted it's now supported.

SuperTech

My opinion is that you should go for it.  It won't hurt to run some vinegar through it. It couldn't hurt.

Suzook

I have a way to go in and out the heat exchanger using the bottom of boiler., but up top in pic, you can see I have shutoffs on return, but on the feed for heat where the circ pump is, no way to shut it off. I'm assuming if I try to pump through the bottom, it would also pump through that circ pump? Hence I NEED A shutoff on that side? Thanks again.

660grizzlyguy

Is the circulator on the correct side of the air eliminator? If you are going to add a valve, maybe think about redoing that as well.

Suzook

660grizzlyguy said:

Is the circulator on the correct side of the air eliminator? If you are going to add a valve, maybe think about redoing that as well.

Technically it's not, but don't want to open that can of worms. Just looking to sweat in a shutoff right after it. System working fine the way it's set up. So I'm assuming a shut off is needed on that end?

hot_rod

Actually You add more scaling minerals after you do the cleaning. Check the fill water quality, hardness, TDS if you can. If it was filled with good quality water, I would let it be.
If anything add a hydronic conditioner product like Rhomar. That will balance Ph, scavenge O2 protect the metals.

Suzook

hot_rod said:

Actually You add more scaling minerals after you do the cleaning. Check the fill water quality, hardness, TDS if you can. If it was filled with good quality water, I would let it be.
If anything add a hydronic conditioner product like Rhomar. That will balance Ph, scavenge O2 protect the metals.

Tds is 130, hardness70. Thoughts?

HomerJSmith

Why in hades aren't you using conditioned water in your sys?

Find a ceiling joist and support that X-tank, for pete sake.

Send a water sample to Rhomar for testing before you commence with the cleaning. The cost may be worth it and you will learn something about your sys.

Suzook

HomerJSmith said:

Why in hades aren't you using conditioned water in your sys?

Find a ceiling joist and support that X-tank, for pete sake.

Send a water sample to Rhomar for testing before you commence with the cleaning. The cost may be worth it and you will learn something about your sys.

Well....I corrected the post and stated, its an old pic during install. Tanks IS supported. And why am i not using conditioned water? I figured i would be fine with a simple flushing of HX every 2 or 3 years. I guess everyone has an opinion. Im also thinking of doing a complete flush, then a refill, and then a treatment with Rhomar. Thoughts? Thanks again everyone.

Canucker

Suzook said:

Why in hades aren't you using conditioned water in your sys? Find a ceiling joist and support that X-tank, for pete sake. Send a water sample to Rhomar for testing before you commence with the cleaning. The cost may be worth it and you will learn something about your sys.

Well....I corrected the post and stated, its an old pic during install. Tanks IS supported. And why am i not using conditioned water? I figured i would be fine with a simple flushing of HX every 2 or 3 years. I guess everyone has an opinion. Im also thinking of doing a complete flush, then a refill, and then a treatment with Rhomar. Thoughts? Thanks again everyone.

Absolutely do that. Fill it with demineralised water, add the chemical treatment and you probably won't have to do much other than test the levels for a number of years. Unless you get a leak, obviously.

Suzook

Well I was gonna do a refill of my tap water after flushing, then add rohmar.

fenkel

Rohmar recommends either deminerized  or deionized water..
They claim both work well with their chemicals..

Suzook

Sort of a funny story. As this thread is goin on, my buddy who is a plumber, had a callout for this exact same boiler. Kept throwing codes, and shutting off. What was going on was the inside of HX needed to be cleaned. Vacuumed out, and cleaned. Said after 3 years it was pretty dirty. Guess i will be adding that to the list. HE said on this boiler its a bit of a pita.

Suzook

I vacuumed out the inside of hx. Wasn't too bad. Just need to flush out the inside this weekend.

Ironman

That HX needs more than vacuuming.

Suzook

Not sure what happened to my post. I cleaned it with water, and a stiff bristle brush. Then vacuumed.

mattmia2

So what is the service for these? I've been meaning to ask. The maintenance section of the manual seems to have been copied from a water tube tankles water heater.

Suzook

mattmia2 said:

So what is the service for these? I've been meaning to ask. The maintenance section of the manual seems to have been copied from a water tube tankles water heater.

Same as most ModCons. Flush out water side of HX, clean out fire side of HX, clean condensate trap, check combustion. Its pretty simple. It is odd that HTP doesn't mention cleaning out the fire side. I guess they "assume" the design of the fire tube somehow miraculously cleans itself. 2 hrs of time, every few years, is worth doing it.

mattmia2

Yeah, the fire side is what I don't know how to do, especially with those fins. The water side I really don't see getting fouled up in a sealed system with modern emitters.

Suzook

mattmia2 said:

Yeah, the fire side is what I don't know how to do, especially with those fins. The water side I really don't see getting fouled up in a sealed system with modern emitters.

Mine were just gunked up on top, as seen in the pic. A stiff bristle brush with water worked for me. Some use clr, or vinegar. I guess if left neglected it would get bad further down the tubes, and you would have issues getting them clean.

mattmia2

I'm not super excited about everything being on the pressure side of that blower from the mixed air/fuel to the products of combustion especially with a lot of difficult to inspect/verify o-ring and flange type joints.

Suzook

Well every boiler seems to have it's pluses and cons. Like stated, it's very easy to work on. I believe with propper maintenance, it should last many years. If your that concerned, just clean it annually, that should keep the hx in decent shape.

Suzook

So I flushed hx yesterday, and there definitely was some gunk. So a freshly cleaned fire side, and water side now. Guess I will do this every 2 years. Pretty simple, maybe 2 hrs total time. Tomorrow, I will double check combustion, make sure it's still good.