Viessmann Solar Collectors Pressure Issues: A Warning & Cautionary Tale

Good morning,

let this thread be a CAUTION to others!

We have a solar installation with 2 Viessmann collectors, which is quite unusual because the tank (250 l) is placed in the attic, horizontally. This resulted in the fact that it was not possible to supply the heat exchanger inside the tank with solar fluid. Instead, there are two circuits (one with a pump and solar fluid and the other, flooded with water, behind the external heat exchanger).

About two years ago there was a problem of the pressure drop on the manometer to zero at low temperatures. As soon as the sun came up, the installation came to life (pressure increased, water was heated). Unfortunately, it was ignored by my father, until the pressure indicated on the pressure gauge was still 0 even with quite strong sunlight. pump fluid into the system, which caused the safety valve to operate, and then found that the pressure gauge "blocked something" and therefore indicated 0, although the system was still under pressure. So they changed the pressure gauge, I think they vented the installation and went.

Unfortunately, a few weeks ago, I was in the attic, by the way, and by accident I noticed that something was wrong - the pressure on the pressure gauge was zero again. Moreover, when the air temperature was negative, the sun appeared, the collectors got hot, and the controller switched on the solar fluid circuit. Interestingly, on the pump unit indicators the return temperature (after the solar pump) was higher (!) Than on the supply (about 15 degrees on the supply, and 40 degrees on the return). The pump was hot, the pipes downstream of the pump (towards the collectors) were hot. Heat exchanger completely cold, tank circulation pipes also cold.

What we did - we turned off the entire controller because I was concerned that the pump might be damaged. We found that there was no pressure (only a little fluid spilled out when the valve was opened). I poured it into a cup, put it in the freezer. The effect after an hour is a dark brown slush. So I ordered a new solar fluid and a filling pump.

Unfortunately, after ordering the pump and fluid, it turned out to be the case the frozen liquid burst (!) the vent at the collectors and torn the flexible pipe connecting the two panels . Failure visible through binoculars from ground level. Let this thread become a warning to other users of the installation. After reading my story, everyone can probably conclude that "experts" should immediately notice that the fluid has changed color and recommend its replacement, or check its freezing point with a refractometer. Unfortunately this did not happen - They just stammered that it is dark, but nothing about the possible consequences. And they also charged 250 zlotys for the entire operation. And then my father did not know that this meant that the fluid was only fit for replacement. It turns out that in Poland you should know everything, because it is difficult to find real professionals ...

In addition, we noticed that the panels are not mounted at the same height, through the flexible tube, which should be straight, is strongly bent. When we go out on the roof, I'll put some photos. This is why it was torn out of one collector.

The company is an authorized installer of Viessmann, province. Lower Silesia, town on B., company XX. I am considering sending an official letter to the Polish branch of Viessmann. I do not count on the money, because the installation is 8 years old, but let them at least be aware of the problem and that they have such bugs for an authorized installer.

Regards and I do not wish to contact this company,
MK

Basic question: who flooded this liquid that then froze?

Do you know 8 years and no service? After all, fluid replacement occurs every now and then, not that it is forever. You called the crew for repair, not a regular service, so they fixed the fault. Unfortunately, the fault is on your side.

Original fluid flooded during installation by the same company. It looks like it was overheating a lot, but that would be quite strange, because from what I've read recently, it would have to be operated at a very high temperature for a long time for it to lose its properties and turn completely dark. I only know that at the very start there was a situation that the pump did not work and the collectors were exposed and the thermometer on the pump group ran out of scale (it was something like 200 degrees), but now we do not remember if the color of this fluid changed then (and what she was at the beginning). We just didn't really care about technical details back then, we trusted the experts in a way, because these collectors were, in a way, unknown to us (electricians). Only then did we start to be interested in the subject.

There are anhydrous fluids. Which are durable and resistant to overheating. But every device needs service and maintenance from time to time. It cannot be otherwise. Without it, then I am surprised why such a scale of damage and the high cost of repair.

@kkknc , yes, but if someone deals with the service / repair of such installations, he should probably immediately notice that the color of the fluid indicates its wear and recommend its replacement. It was summer then, and you could easily change the fluid. From what I read, it's a fluid change every 8-10 years. We did not receive any warranty card that would mention the reviews. I believe that a professional company should provide written information about such reviews. When we change the oil in the car, there is a note about the date / mileage until the next change.

PS There is also the issue of assembling the collectors, which I mentioned. I put a photo - admittedly from a distance, but you can see what's going on.

Are you sure frozen fluid was the cause? Maybe the reason was clogging of the circuit by fluid deposits? Do you have an expansion vessel in this collector circuit?

Not. I can see from the other side. You can always make the customer aware of or mention procedures and services. But generally nothing by force. I want to fix the reported fault, ok. But I can't get enough of a quarrel from a customer who knows everything only to fix it. The old rule of overzealousness inferior to fascism. And I do not come out in front of the line.

@Sstalone yes, there is an expansion vessel. The solar pump would be able to burst the vent with a blocked system? Besides, there is a safety valve, it should come off at 6 bar. Besides, I was checking the solar fluid, it froze in the freezer.

Mr. buddy
how much did you save on these installations?
in amount?

kkknc wrote:

I want to repair the reported fault approx.

Well, the client reported, gave symptoms and experts

swistak40 wrote:

found that the pressure gauge "is stuck with something"

It does not appear from the text that the customer reported the need to replace the pressure gauge

swistak40 wrote:

Good morning,

let this thread be a CAUTION to others!

Exactly. Solar installations are inspected every year. The density of the fluid is controlled by a refractometer and based on this
a decision is made to replace the solar fluid, approximately every 5 years.
The service technician checks the pump, air vents, controller settings, pressure in the expansion vessel.

swistak40 wrote:

We have a solar installation with 2 Viessmann collectors, which is quite unusual because the tank (250 l) is placed in the attic, horizontally. This resulted in the fact that it was not possible to supply the heat exchanger inside the tank with solar fluid. Instead, there are two circuits (one with a pump and solar fluid and the other, flooded with water, behind the external heat exchanger).

Some "invention", if made in accordance with art, does not have to complicate the operation of the system.

vodiczka wrote:

About two years ago there was a problem of the pressure drop on the manometer to zero at low temperatures. As soon as the sun came out, the installation came alive (pressure increased, water was heated). Unfortunately, it was ignored by my father, until the pressure indicated on the pressure gauge was still 0 even with quite strong sunlight. pump fluid into the system, which caused the safety valve to operate, and then found that the pressure gauge "blocked something" and therefore indicated 0, although the system was still under pressure. So they changed the pressure gauge, I think they vented the installation and went.

A bit of guerrilla warfare, but how do you comment on that?
If there was no colleague at the same time, maybe they wrote in the protocol what they did?
What did they pump this fluid with that they did not have "own" pressure control ??

swistak40 wrote:

Unfortunately, a few weeks ago I was in the attic and I accidentally observed

Jokes? After the repair, my colleague did not check - did he check if the system was working properly ???

swistak40 wrote:

What we did - we turned off the entire controller because I was concerned that the pump might be damaged. We found that there was no pressure (only a little fluid spilled out when the valve was opened). I poured it into a cup, put it in the freezer. The effect after an hour is a dark brown slush. So I ordered a new solar fluid and a filling pump.
Unfortunately, after ordering the pump and the fluid, it turned out that the frozen fluid burst (!) The vent next to the collectors and torn the flexible pipe connecting the two panels. Failure visible through binoculars from ground level. Let this thread become a warning to other users of the installation. After reading my story, anyone can probably conclude that

The owner of the installation neglected the periodic inspections of the installation, 8 years ????? and the car is once a year.
The owner tried to diagnose and fix the problem on his own.
The owner is looking for the culprit, "Because they didn't tell him" Because for savings, I DON'T WANT to spend around PLN 200 for the annual inspection
Because he bought "Pompke" and he will replace the fluid itself. And he doesn't even know what kind of liquid!
And finally it states on the forum that

swistak40 wrote:

"experts" should immediately notice that the fluid has changed color and recommend its replacement, or check its freezing point with a refractometer. Unfortunately that did not happen - they just stuttered that it is dark, but nothing about the possible consequences. And they also charged 250 zlotys for the entire operation. And then my father did not know that this meant that the fluid was only fit for replacement. It turns out that in Poland you should know everything, because it is difficult to find real professionals ...

Not true
It turns out that some things have to be taken care of personally (... and my father did not know ...)
Read and follow the operating instructions.
Ask a specialist for references, about working time in the profession, and not only about the cost of the service.

swistak40 wrote:

In addition, we noticed that the panels are not mounted at the same height, through the flexible tube, which should be straight, is strongly bent. When we go out on the roof, I'll put some photos. This is why it was torn out of one collector.

????? for 8 years you didn't get interested in how the panels were installed?
Didn't you pick up the work done 8 YEARS BEFORE ?????
And now, how did the experts determine the cause of the failure ...

swistak40 wrote:

The company is an authorized installer of Viessmann, province. Lower Silesia, town on B., company XX. I am considering sending an official letter to the Polish branch of Viessmann. I do not count on the money, because the installation is 8 years old, but let them at least be aware of the problem and that they have such bugs for an authorized installer.

For 8 years they weren't bastards, just now ??? Strange.
Send, they will be aware that for 8 years you have not become interested in the correct operation of the system.
you are not interested in checking and maintaining the system.
And now you're looking for a scapegoat to blame YOUR neglect on.

I did not write this to defend the installer (I believe that they did not exercise due diligence during the visit)
but what a colleague described is a typical example of a customer pouring down operational recommendations.
And in the event of a breakdown, forceful search for the culprit. Of course, everyone else is to blame but not "me"
They took PLN 250 - yuck
They should come to change the fluid pressure gauge and pay at least 100 PLN that the client called them
How dare they ask for money for their work ???

Okay now come on
Before further use it is necessary to:
1 Repair any leaks in the system
2 Replace ALL seals
3 Perform a pressure test
4 Flush the system with the old fluid
5 Fill the installation with new fluid
as recommended by the system manufacturer
6 Bleed the system
7 check the system operation

Check the system every 12-18 months
Mandatory refractometer.
If a specialist does not have a refractometer, get him out of the house
If a specialist does not have an electric pump to fill the system - drive him out of the house
If the specialist does not issue a report on the work performed - drive them out of the house

greetings

Last year, in the spring, I did a review and modernization of the system in Belgium for a friend. Come here because it doesn't work. On the spot, it turned out that he had drained the water from the exchangers, and by the okaji the liquid of the panels also ... the sun came and the sensors on the collectors were baked and the fun was over.
Under no circumstances should these systems be drained of fluids. The ends of the exchanger rods in full sun can reach over 200 degrees .....

Hello,
I don't know what it may depend on, but ...

I have someone in my family who has a solar installation. Vacuum, controller, 2 thermometers, large heat exchanger and a lot of fluid that does not boil so easily, but does not freeze.

Effect?

Over 15 years without breakdowns or servicing. (apart from the fact that once crows ate the lagging on the pipes and made a nest on the pipes :P


So dear ... can anyone explain what kaman kolektoyr have been operating for over 15 years without service? The liquid does not freeze and nothing is leaking ... I don't know anything anymore

I have been flooded with the installation of something ala "Glycol" for several years and I have never had any problems, whether in winter or in summer.
It does not freeze and does not boil!
I propose without pipes, flood the installation to the given pressure, which is given by the manufacturer.

PS: the color of the liquid changes very quickly!

https://motofocus.pl/informacje/nowosci/10302...ze-evans-waterless-coolants-dostepne-w-polsce

Hello

How often to change the solar fluid is specified in the details on the product, e.g. 5 years. I changed the solar fluid TERMSOL EKO in HEAWLEX collectors and it says " expiry date 5 years (years from the production date) and the date stamped on the label to describe the product.

After refilling (replacing) the fluid to the appropriate shade on the manometer (how many "bar" is specified by the manufacturer of the instance), fill it in appropriate conditions, ie when it is overcast or covered with sunbeds, eg in HEAWLEX collectors, fill up to 2.5 bar. Then vent several times (sensor housing type with a vent at the solar input). Too large temperature difference between the collector input and output may indicate bad deaeration or pump failure.

Sensor housing with vent


Greetings.

I am not a specialist in this topic. I also have a solar installation, three panels and a controller and everything that ensures the operation of this system. The antifreeze fluid used for solars is propyl glycol. I am 10 years old, the same liquid and it has not changed color, does not freeze, this year I will replace it with the same one. If the system is automatically controlled, then in winter, when the temperature is lower than 3 degrees, the control system pumps the fluid through the collectors by itself, so why did it freeze?

alfred47 wrote:

The antifreeze fluid used for solars is propyl glycol. I am 10 years old, the same liquid and it has not changed color, does not freeze, this year I will replace it with the same one.

10 years is too debt, probably that's what the manufacturer of the fluid says. I have 5 years.

Added after 34 [minutes]:

alfred47 wrote:

If the system is automatically controlled, then in winter, when the temperature is lower than 3 degrees, the control system pumps the fluid through the collectors by itself, so why did it freeze?

You don't necessarily have the winter option turned on.

I turned off this option right at the beginning and I live in the Bieszczady Mountains and the frosts are also quite good and I never felt cold. In 2010 it was 28 minus for a week and nothing happened. I find it strange that the liquid changed color so quickly and froze. I worked for over 40 years in a car service, when the liquid was not baptized with water, nothing happened, I had a case when the liquid was too diluted, the water froze and it was made of ice and it floated, e.g. borygo. When they have such large frosts, they can flood the liquid down to -60 degrees, for example, Antifreeze is a thick Russian glycol in Siberia flood it. Why is it impossible to pour car fluid because the heat transfer values are different.

kiss39 wrote:

10 years is too debt, probably that's what the manufacturer of the fluid says. For me it is given 5 years.

The manufacturer gives the period of operation with a safety margin, Good-quality liquids easily last 2-3 times longer.
To be sure, after the deadline specified by the manufacturer, you can perform a verification test before each winter.

alfred47 wrote:

I turned off this option right at the beginning and I live in the Bieszczady Mountains and the frosts are also quite good and I never felt cold. In 2010 it was 28 minus for a week and nothing happened. I find it strange that the liquid changed color so quickly and froze. I worked for over 40 years in a car service, when the liquid was not baptized with water, nothing happened, I had a case when the liquid was too diluted, the water froze and it was made of ice and it floated, e.g. borygo. When they have such large frosts, they can flood the liquid down to -60 degrees, for example, Antifreeze is a thick Russian glycol in Siberia flood it. Why is it impossible to pour car fluid because the heat transfer values are different.

Supposedly, our pumps are not adapted to thick glycol. I don't know anything about it, but I read somewhere that solar glycol is less harmful than the liquid from your car in the event of damage to the coil in the boiler (DHW tank)

I used an additional pump and plate exchanger for everything between the hot utility water tank and the fluid circuit in the solar panels. Failure of the exchanger and coil at once is practically impossible

rrad wrote:

(Supposedly, our pumps are not adapted to thick glycol. I don't know anything about it, but I read somewhere that solar glycol is less harmful than the liquid from your car in case of damage to the coil in the boiler (DHW tank).

Everything is correct, I also have the solar collectors flooded (with propyl glycol) and not with car fluid, this is what is recommended because it transports heat better, and the car fluid is better suited for cooling.
As far as the exchanger is concerned, it is not so completely because there is a heat loss of up to 5% in the exchanger. I also had an exchanger for some time, but it was because I had a new tank and it was connected to central heating.

alfred47 wrote:

I also have solar collectors flooded (with propyl glycol) and not with car fluid, this is what is recommended because it transports heat better, and the car fluid is better suited for cooling.

You're right, solar fluid transports heat and car fluid cool :)

Propylene glycol (non-propyl) is much less toxic (the manufacturer says it is non-toxic) than ethylene glycol. It is also used as a car fluid - Borygo Eko.
https://www.borygo.pl/produkty/borygo-eko

welcome back

I have a question for colleagues, do you have an automatic vent at the collector on the roof (top), and how is it and if it works.

When it comes to information about the properties of the fluid used for solar panels, I received this information when I bought it and later read it on the Internet. And I did not check the accuracy of the information. But there is something about this information

Added after 4 [minutes]:

I did not have this type of vent. According to the information from the vendors of these devices, automatic deaeration is not used during installation because it becomes covered with crystalline salt when the liquid evaporates, and may cause air to the system.

Added after 3 [minutes]:

When it comes to harmfulness, you are also right because it is used as an additive to drugs, such as Diclofenek

kiss39 wrote:

welcome back

I have a question for my colleagues, do you have an automatic vent at the collector on the roof (top), and how is it and if it works.

Probably a long time ago, system manufacturers moved away from automatic air vents on the roof, switched to manual and added a gas separator at the pump or somehow it is called.