# HTP ModCon boiler



## Greenguy (Jan 22, 2011)

Working in a commercial building right now separating the combined sewer, boss informed me I would be starting to install a new ModCon boiler within 3 weeks. 

Does anyone have any experience or thoughts on them, any flaws should know about before I get started, taking out two stupid hot boilers (2000k btu a piece) one of which has been condemned the other still works and installing the ModCon 850 in there place.


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## Plumbworker (Oct 23, 2008)

htp makes some good boilers never put in a mod con but i've installed many muchkins


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## Scott K (Oct 12, 2008)

Do these boilers have the Giannoni heat exchanger? Typically a lot of HTP products do (for the most part anyways). I'm not much of a fan of this exchanger for a lot of reasons. Also keep in mind you're probably replacing boilers with low head loss with a high head loss heat exchanger (if it's a water tube mod-con whether it's the Giannoni water tube or not). This could require changing out pumps to ones with higher head to deal with the high head loss and to maintain the flow rates to get heat out of the boiler otherwise it won't perform as it should. 

Does your boss have any leeways towards which boiler he can select, or has his or the clients mind already been made up?

Also, you said you're taking out 2 boilers and it sounds like you're replacing them with 1 based on how you worded it. Assuming this is true, has any consideration been given to redundancy of the boiler plant and putting 2 smaller boilers in their place instead of 1 large boiler? Have you ever tried servicing one boiler that serves a large building? Can you say night shift (especially if it's heating an indirect) and if anything goes wrong....

If you have any chance to change the boiler or influence the change, have a look at the Cleaver-brooks clearfire modulating condensing boiler. It's a little bit heavy (about 1400+ pounds, however most are quite heavy in this class as well) but it is honestly one of the best built mod-cons in its class (I would argue better than the Viessmann Vitocrossal for many reasons), plus it's got a low head loss fire tube heat exchanger so it doesn't require as much pumping power to move heat, which means you might not have to change out a pump. It's got one of the highest grades of stainless steel you can get in the heat exchanger (316 Ti) plus the fire tube's are lined with aluminum really which aids heat transfer, and it's easy to service.


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## Greenguy (Jan 22, 2011)

Scott K said:


> Do these boilers have the Giannoni heat exchanger? Typically a lot of HTP products do (for the most part anyways). I'm not much of a fan of this exchanger for a lot of reasons. Also keep in mind you're probably replacing boilers with low head loss with a high head loss heat exchanger (if it's a water tube mod-con whether it's the Giannoni water tube or not). This could require changing out pumps to ones with higher head to deal with the high head loss and to maintain the flow rates to get heat out of the boiler otherwise it won't perform as it should.
> 
> Does your boss have any leeways towards which boiler he can select, or has his or the clients mind already been made up?
> 
> ...


 
I wish i had leeway, at present on site they have two 2000k Btu stupid hot boilers, the engineer on the project specced this unit. won't get a chance to change it, personally i would have rather put in two smaller units like a Viessemann, they do have some decent systems or the new IBC SL80-399, so if one goes down they still have heat. Like i said in the orginal post been asking around and none had installed this unit, i just want to make sure im not walking into a dud unit.


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## ZL700 (Dec 8, 2009)

Plumbworker said:


> htp makes some good boilers never put in a mod con but i've installed many muchkins


Mod con = modulating condensing

That's what a munchkin is


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## Michael J (Sep 13, 2008)

I installed a Mod Con for a snow melt system two years ago. Found the boiler to be fantasic, no problems on the install, they are a Munchkin on steroids. Watch out for the supply and return nipples, they seem loose when installed but hold just fine. You can stack one on top of the other if you have floor space problems.
You'll love them


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## Plumbworker (Oct 23, 2008)

ZL700 said:


> Mod con = modulating condensing
> 
> That's what a munchkin is


 LOL you misunderstood me... I've installed and maintain many modulating and condensing boilers. I meant i have not installed HTPs "MOD CON" series of boilers yet


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## ZL700 (Dec 8, 2009)

Plumbworker said:


> LOL you misunderstood me... I've installed and maintain many modulating and condensing boilers. I meant i have not installed HTPs "MOD CON" series of boilers yet


 
MOD CON is not a HTP product or model but a nickname given to all modulating condensing boilers

A Triangle Tube Prestige boiler is a MOD CON, as so many others


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## Redwood (Sep 8, 2008)

ZL700 said:


> MOD CON is not a HTP product or model but a nickname given to all modulating condensing boilers
> 
> A Triangle Tube Prestige boiler is a MOD CON, as so many others


Yep... And you should stick to what you know... :laughing:
Heat Transfer Products "Mod Con VWH Hot Water Supply Boiler™"


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## ZL700 (Dec 8, 2009)

Redwood said:


> Yep... And you should stick to what you know... :laughing:
> Heat Transfer Products "Mod Con VWH Hot Water Supply Boiler™"


I wonder if they got the copyright to that name as its been a common condensing boiler slang term for years in the industry

???


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## Greenguy (Jan 22, 2011)

Finally getting started on this project two days to demo the old stupîd hot boilers, took a lot of sawzal blades and grinder wheels, get the apprentice to remove the waste later this week.


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## Plumbworker (Oct 23, 2008)

how far are your venting runs? combustion makeup & flue combined? thats looks like ferrous system piping i woud be scared to install a low mass unit in that type of piping..


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## Greenguy (Jan 22, 2011)

Plumbworker said:


> how far are your venting runs? combustion makeup & flue combined? thats looks like ferrous system piping i woud be scared to install a low mass unit in that type of piping..


My venting is about 10' vertical 10' horizontal, really short. 
Finally getting started on the job this week
Damn the unit is long and heavy took 5 of us to drop it into place. I start piping it tomorrow.


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## Plumbworker (Oct 23, 2008)

is that a 850?


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## Greenguy (Jan 22, 2011)

Ya, its freaking long compared to what most pics of this system show. Will post some more pics soon, just about got the unit piped into place.


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## Greenguy (Jan 22, 2011)

Some pics, just waiting on a few parts right now like venting, and a air separator, the sparky is going to wire it up next week for me. I still got a bunch of pipe supports to install, and such.


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## Mississippiplum (Sep 30, 2011)

Htp makes some nice boilers


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## Scott K (Oct 12, 2008)

Greenguy said:


> Some pics, just waiting on a few parts right now like venting, and a air separator, the sparky is going to wire it up next week for me. I still got a bunch of pipe supports to install, and such.


The sparky is going to wire what for you?


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## Greenguy (Jan 22, 2011)

the pumps 120 and 220v, electrical is not part of my contract for this job.


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