Need someone to service/modify a Latento hydronic heating setup, Melbourne

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Need someone to service/modify a Latento hydronic heating setup, Melbourne

(15 posts) (6 voices)

Started 4 years ago by dimons
Latest reply from Hydronic jaco

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dimons
Member

Hi
12 months ago we bought a house in Melbourne's inner west. It came with a rather complex combined hydronic heating and hot water system. Having lived with it for a winter and more or less understanding its foibles we now need to make some changes, rather than pulling the whole thing out which one (I suspect lazy) hydronic guy suggested.

We have:
- a Latento XXL heat exchanger, 500L
- Bosch 32 gas booster
- Sunda 32 evac tube
- a temperature difference controller
This feeds a combination of underfloor heating and hydronic panels plus domestic hot water.

The system is not performing all that well - we sometimes run out of hot water, and the heating system struggles to cope in cold weather. Recently we had no hot water or heating because the gas booster wouldn't ignite. The solar component adds complexity without providing much of a contribution in winter.

I still think the system is basically sound. I am sure it needs reconfiguring or fine tuning. Is anyone able to suggest someone who might be able to do this and who is able to provide independent advice, rather than selling a particular product? One thought I have had is to separate the HWS and hydronic systems to simplify both systems and to ensure we at least have hot showers.

Any suggestions appreciated.
Simon

Posted Sunday 3 Sep 2017 @ 3:15:30 am from IP #
munter
Member

Combined systems present greater challenges than separated DHW and hydronic but with the potential for even better efficiency. We made the call to separate ours during the build as the risk of cold showers was quite a concern. It sounds like you have a booster issue which might be solveable by simply changing out the gas booster though I guess there could be a number of other issues also. As a complex system, unless you can find the original supplier/installer you are probably going to have to accept someone coming in on a “best efforts” basis and without a watertight guarantee that they will correctly diagnose and solve the problem. Your best bet might be to find a cooperative and flexible plumber who you are happy to work with or alternatively, perhaps latento might be able to suggest appropriately qualified plumbers?

Posted Monday 4 Sep 2017 @ 1:45:47 am from IP #
dimons
Member

Yes I agree that combined DHW and hydronic systems can be an issue if something goes wrong. Then you lose everything.

I have spoken to the original installer who basically said "that seemed like a good idea in 2010 but I wouldn't do it now". Which didn't give me much confidence when he then said "just pull it out and start again". Understandably I'm looking for a second opinion - as you suggest a cooperative and flexible plumber to work with.

Does anyone have any suggestions for such a plumber willing to service Inner west Melbourne?

Posted Monday 4 Sep 2017 @ 2:15:47 am from IP #
arttt
Member

The problem you will have is that you have a complex system and while it doesnt take a rocket scientist to sort it out it is probably a few steps more complex then 99% of plumbers are capable or willing to deal with.
So you are going to struggle to find someone with the skills and all indications are that the original installer might not have had the skills either. There is a good chance he got something wrong in the install.

Plumbers are also often unwilling to spend a lot of time and charge you a lot of money on something they are not confident they can get right and risk many call backs. The original installers pulling it out and starting again comment is a common expression of a plumbers pragmatic approach.

I hope you manage to find this mythical plumber that can, and is willing to, sort it out but my impression is that if you want to sort the system out you probably need to do the hard yards yourself. You will need to become an expert in the system to first understand how the manufacturers think it should installed, function and if it is capable of meeting your needs. Then you need to study what is actually in your house and identify if the installation was to standard or if there are parts that arnt functioning. Once you have identified what exactly needs doing then hopefully under your careful direction any plumber can make the changes needed.

It depends where you fit on the plumber to rocket scientist continuum if the above is possible.

Posted Monday 4 Sep 2017 @ 2:54:46 am from IP #
dimons
Member

Good advice about becoming an expert in the system myself. That's why I've waited 12 months so as to understand more about it before even thinking about making any changes.

However I'm forced into doing something now as the gas booster component is playing up. I have today called in a commercial outfit (Pheonix Gas Co, Bosch Agents) who hopefully will get the gas booster running reliably & while they're out here I'll get their opinion on possible further suggested changes.

Buying a house with complex technology is great while it all works but a bit of a nightmare when it doesn't. (We also have a greywater system which seems more trouble than its worth, given we have massive rainwater tanks as well.)

Still interested in hearing from anyone who has got a Latento system or knows someone with the skills to work on one, if they exist.

Posted Monday 4 Sep 2017 @ 3:57:17 am from IP #
axess
Member

dimons,

Do you have any operating manuals for the system? The manuals should give basic trouble shooting and operational information.Good manuals should also give accurate performance information as well.
Combining a slab/ heating system with hydronic panels seems a bit odd since the operating temperatures are usually quite different. Add a solar component with a separate? booster also seems overly complex. I also assume you have some kind of heat exchanging compound water tank with maybe 3? drawoffs, all at different temperatures. Would it be possible to step back a bit and isolate some of these functions? Munter's point about separate hot water might be a good place to start.

Posted Monday 4 Sep 2017 @ 8:07:56 am from IP #
dimons
Member

Sadly I wasn't left with any manuals when we bought the house, so I have had to do my own research. Fortunately most of the info can be found online with persistence.

The combination of slab heating downstairs and hydronic panels upstairs is controlled via a partage (yes another complexity) which somehow manages to deliver much hotter water to the panels than the floor.

The solar just seems to add complexity, although it did heat the water somewhat last weekend on a grey winters day when the gas unit wouldn't run, so glad to have it.

Agree about the desirability of separate hot water & it's been suggested that the solar evac tubes could be allocated just to heat that, rather than the hydronic system where it can't contribute enough heat to make a difference. That would mean a separate storage tank for DHS and maybe a second gas booster dedicated to hot water, so not a cheap fix I assume.

Posted Monday 4 Sep 2017 @ 10:16:55 pm from IP #
Greg
Member

There would be hydronic companies in Melbourne that should be able to help. Since the Latento is just a stratified storage tank (wrapped with eutectic wax I think), if you are not getting enough heat then you are either not putting enough heat in, or taking too much out.
Can you do some calcs or have you collected some data?
If you know your inlet water temps and what your heat supply needs are, then a few back of envelope cals might help.
It just sounds like in winter the solar does not generate enough heat so its all up to the gas heater . So that is probably what you need to look at.

I did these rough calcs for my system:
0.72 - 1.8MJ/tube/day (winter - summer) from evacuated tubes.
I have 30 tubes so, 21.6 - 54MJ/day
325 l DHW tank with inlet temp in winter in the single digits (rainwater tanks) means worse case is 28C in winter, 70C in summer.
In winter I boost with a wetback or electric element if the fire is not on.

So I'm guessing 32 tubes is for domestic hot water with gas to boost in winter would be ok.

The bosch 32 (Commercial heater ?) should produce a max of 57.5kW @ 50C. You'd need to have calcs for your winter heat load to know if it will cope.

I'm sure you conquer it !
Edit: Just found the Latento brochure and since all heat in and out is via heat exchanger pipe the tech info state that the heat generator must be 15C higher than the hot water out. So if you want DHW @ 50C you need your Latento heat storage to be at min 65C. The way I read it if the Bosch produces a max 50C you may always struggle in low solar days.

Posted Tuesday 5 Sep 2017 @ 12:13:58 am from IP #
arttt
Member

So further to what Greg said about back of the envelope calculations.
Once you have the gas booster working again it should have no problem providing enough heat for hot water and the space heating (if you need more then 57kW then you have bigger problems then the heating system).
There should be a way to switch off and isolate the solar system pipes. If you do that for a bit then that will simplify things for troubleshooting. you can add it in again later if the rest is resolved.

Next you need to get a handle on the maximum heat that you need. So estimate the volume of hot water you use each day and the temp it is at. Also estimate the heat flux out of the house. There are other threads on this forum that detail these calculations.
Dont forget to account for long periods of open doors etc
Also if you have some sort of pumped ring main they can be a big waste of heat.

Then look at the heaters installed and check that their capacity roughly adds up to the maximum heat flux through the house. You will need to do some googling to work out the heat flow out of the slab heating. Alternatively this can be calculated if you know inlet and outlet temperatures and the flow rate - this is a good double check.

So
If the heaters are not big enough to match the heat flux out of the house then that is a problem.

If the heat flux out of the house + the domestic hot water demand is greater then or even close to 57kW then that is a problem.

If the above checks out ok then either the gas booster is not operating to its capacity (faulty or the system isnt telling it to turn on at the right time) or the way the system is plumbed is incorrect. In that case it would be instructive to try and draw a schematic of the plumbing.

Posted Tuesday 5 Sep 2017 @ 12:58:07 am from IP #
dimons
Member

Thanks everyone for these comments. We have just had a repair guy out who has discovered that the Bosch 32 unit is completely clogged with wax, so no water flow.

It's pretty much certain that the Latento storage tank has failed and we now have wax everywhere including in the DHW and the hydronic.It's got to go.

Based on the advice here I think we will quickly get installed a solar boosted hot water service quite separate from the hydronic. That way I can have a shower.

Then I'm going to need a new hydronic boiler and tank, plus the system totally flushed out. Big buck's I'm afraid.

Any recommendations for reputable hydronic companies in Melbourne to get to quote on this?

Posted Tuesday 5 Sep 2017 @ 2:14:46 am from IP #
arttt
Member

on yuck.

I think if i understand the latento system that the DHW and maybe the hydronic should be in isolated loops through the tank so maybe you will be lucky and not have wax in them.

Maybe the wax will be just in the solar and the gas side of the system. fingers crossed.

Have a look at a sanden heatpump for the DHW side of things. Its probably a better option unless you can make use of the existing evac tubes.

Posted Tuesday 5 Sep 2017 @ 2:23:34 am from IP #
Greg
Member

Good news you found it, really bad news about the wax. It'll be everywhere. After the clean out maybe fit one of these to capture any wax still hanging around. https://www.filtersystemsaustralia.com.au/hot-water-filter-housing-suit-high-temperature-hot-water-systems-1-2-port-1-0hw.html

You will be able to start researching condensing gas boilers and maybe heat pumps, oh and of course winning lotto numbers.

Posted Tuesday 5 Sep 2017 @ 2:26:22 am from IP #
dimons
Member

OK finally found out what is going on, and why. I'll document it in case it is of assistance to anyone else.

The Latento tank unit has leaked most of its water through a split in the bottom. This lowered the water level significantly. As a result the paraffin wax which is supposed to float on the top of the water contents was drawn into the Bosch 32, and has basically killed it.

The good news if there is any is that the hydronic system is a closed loop via a heat exchanger in the Latento, so no chance of wax getting in there.

So I'm no longer looking to modify the Latento, but to replace it completely, together with a separate new HWS. So apologies to the guy who I criticised for recommending that in my initial post. Thankfully we at least have a temporary instantaneous HWS rigged up thanks to a plumber who was willing to put himself out to solve our problem.

Also I'd better try my luck with the Lotto as recommended by Greg.

Posted Tuesday 5 Sep 2017 @ 1:00:12 pm from IP #
Greg
Member

Dimons, according to the brochure all heat input and outputs are heat exchangers, so the heat exchange pipe for the bosch must have also burst , maybe due to water loss.
Supposedly you fill the latento , the heat exchangers heat the stored water, the eutectic wax floats to the top sealing the water. It's basically a sealed tank.
Bit of a design flaw that there is no low water alarm.

Posted Tuesday 5 Sep 2017 @ 11:32:15 pm from IP #
Hydronic jaco
Member

Hi, the phase changing material on top off the tank melts at 65 C providing better heat absorption and over heat protection. The xxl has 3 loops: 1 from and to solar, 2 domestic cold water via loop to hot tap outlet , and 3 flow and return heating loop.I my self and fixed latento tanks before and from what i have seen company's take the wax out of the tank because the only way to bust your internal water temperature is to use a buster that recirculates the storage water.So simply speaking your hot water, hydronic heating, are separate heat exchanger coils submerged in the tank taking energy to your desired destination, and the solar coil just gives it an extra bust.So in your case they left the wax inside the tank, and the wax would melt, and run in a semi/liquid form through the bosch buster heat exchanger, and that's not good.But on the other side if the is no heat dump/ overheating protection in the initial design consideration, and you take the material out the tank will burst.The system it's self is a open, un-pressurized tank with a header tank topping up the water level.Solar thermal combi systems like this are very efficient and are widely used in Europe, and you can't tell me they don't work well because at - 15 c you need heat and hot water. The conclusion is as some one mention above that 99.9% of plumbers don't have a clue and i see this on a daily basis.Growing up in Germany,and coming from a family of heating installers,i can say that proper design and competent tradesmen are paramount.If you wold like any advice on your system let me know, we install Solar thermal combi hydronic system in Melbourne

Posted Saturday 23 Sep 2017 @ 10:31:43 am from IP #

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