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Tony
10-05-2005, 12:07 AM
Ok, here's the story.

We've got a Beasley solar water heating system - panel on the roof, big water tank in the house, small vent pipe on the roof. It was installed when the house was built, about 3 years ago. Works really well - no water heating bills from about September through March-April.

We turned the immersion heater on a couple of weeks ago, and a few days later water started erupting from the vent pipe on the roof in 30 second bursts every 10 mins or so. Went on all night and stopped in the morning.

Last Saturday we turned the immersion heater off because it was a sunny day. In the evening the venting happened again, over a period of about 30 mins. I called the installer who said it might be the thermostat gone bung and it was boiling, though there was no other evidence to support that (we have a temperature gauge panel on the wall), and also the power consumption was not out of the ordinary.

This evening it started again (immersion heater was on). 30 second bursts every 6 mins. This went on for a while, and we turned the immersion heater off. Stopped for a while, then started venting continuously.

If we turn on a tap, (hot or cold) it stops then starts again if the tap is turned off. As far as I can tell it is cold water being vented (at least it is now).

We are on tank water, and while most of the water is just running back into the tank, some is getting lost, which is not good. What is more worrying though is that the pump is running continuously, which can't be doing it any good. I've turned the pump off for the night, and I'll be calling the installer in the morning, but I thought I would call on the assembled expertise of the Press F1ers to see if any one has any suggestions as to what might be going on.
:confused: :confused: :confused:

somebody
10-05-2005, 08:52 AM
I'm not a plumber, but when our (normal) hot water cylinder was doing it, it was because the low-pressure-limiter was dying - ie. water pressure was too high for the cylinder to cope with (At the particular water temperature), so it started spewing out the vent pipe. Coupled with a low air temperature, it made matters worse.

Greg
10-05-2005, 10:58 AM
Sounds like a valve problem - forget what it's called.

Tony
10-05-2005, 11:58 AM
Sounds like a valve problem - forget what it's called.I think you are right - see previous post.
I've talked to the installer this morning and their resident expert is on holiday. The boss is going to try and contact him to discuss what might be happening. In the meantime, so far today it has been OK - but wait till evening...

Winston001
10-05-2005, 01:33 PM
Tony - is your system pressurised or gravity feed? If pressurised then Somebody is on to it. The water has to be forced out somehow and the choices are:

Incoming water, or

Steam pressure. :eek:

Tony
10-05-2005, 02:09 PM
Tony - is your system pressurised or gravity feed? If pressurised then Somebody is on to it. The water has to be forced out somehow and the choices are:

Incoming water, or

Steam pressure. :eek:The system is pressurised, but it was venting last night when the water temperature was waaaay below boiling. The water coming out was cold. It all seems a bit of a mystery. The installer's expert is coming to see us tomorrow (poor guy has been pulled off holiday!), so we'll see what happens then. It is interesting that it only seems to be happening at night, so ambient temperature might be a factor - but it wasn't cold enough to be frosty.

Winston001
10-05-2005, 02:27 PM
Odd that it is intermittant but sounds like a developing failure of the pressure relief valve. Might have a bit of dirt in it, but it shouldn't have got there in the first place.

The reason it is venting is that this valve is letting water out as fast as it comes in from the pressure pump. The water simply visits the cylinder on its way through to the great outdoors. :D

Nothing to do with boiling, although I'm sure you know that. Sounds like a plumbers job.

Tony
10-05-2005, 02:45 PM
The reason it is venting is that this valve is letting water out as fast as it comes in from the pressure pump. The water simply visits the cylinder on its way through to the great outdoors.That's certainly my suspicion as to why it was doing it non-stop last night. It's the stop-go thing that has me confused.
:confused:

Graham L
10-05-2005, 03:22 PM
The stop-go will be because there is air in the system acting as a "spring".

george12
10-05-2005, 06:27 PM
It's probably whatever is causing the pump to run continuously.

Pump runs continuously -> pressure rises -> gotta vent

Find out why that is.

pctek
10-05-2005, 09:47 PM
My partners a plumber.
He said
A) not enough symptom descriptions
B) Its probably the thermostat
C) The temperature gauge thing you have doesn't mean s***
He says ring him 8328654

Jester
10-05-2005, 10:07 PM
I'm not a plumber, but the valve is called an Ajax Valve, which is a pressure releasing valve, generally brassy in colour, with a rubber diaphragm in the centre.

These are generally located on the hot water cylinder in a standard electric cylinder installation. They can fail, spurting water out of the roof / not allowing pressure to release = big bang / blow water out, flooding the house.

I saw two houses today where they were flooded as a result of failure of the Ajax valve.

Info added as a general FYI .... Your installation sounds different to this set up though.

Greg
10-05-2005, 11:07 PM
the valve is called an Ajax Valve
Thanks Jester... that's the beggar I was thinking of.

Ours was replaced which cured symptoms similar, but not identical to, the ones that Tony's experiencing.

Tony
10-05-2005, 11:54 PM
My partners a plumber.
He said
A) not enough symptom descriptions
B) Its probably the thermostat
C) The temperature gauge thing you have doesn't mean s***
He says ring him 8328654One of my initial suspicions was the thermostat, but the fact that it has been happening when the immersion heater was turned off seems to argue against that. The "temperature gauge thing" is certainly not an accurate indicator of the water temperature, but it does show whether the temperature is going up or down. Why does he think it is a total waste of time?

tweak'e
11-05-2005, 12:04 AM
well the way i see it its either boiling and blowing the valve (which is easy to see due to the steam comeing out) or the seal in the valve is stuffed in which case change the valve.

the problem we useally have is the wetback boils the tank which pops the valve then the pressure from the pump keeps the valve open so it pumps the water out all day long :(

Tony
11-05-2005, 09:19 AM
the pressure from the pump keeps the valve open so it pumps the water out all day long :(I think that is what happened when the continuous venting was occurring. As I write, (8:13 a.m.) there has been a series of venting events since I got up this morning and turned the immersion heater on, but it seems to have stopped now. :confused: :confused: :confused: :confused:

Tony
11-05-2005, 01:18 PM
We've just had the supplier expert visit, and this is his analysis:

When the system was installed, our plumber installed a frost valve, but put it in the wrong place. It should have been attached directly to a lower corner of the solar panel, but in fact was installed at the highest point of the system into the outlet pipe! As a result it has constantly been exposed to hot water that it was never designed for, and has eventually failed.

The remedy is to replace the failing frost valve with an air bleed as it is the highest point of the system, and to install a frost valve in the proper place.

Reid Technology who supplied the system have been extremely helpful in sorting this out, and they certainly have our recommendation.

Pctek, we will be using Reid Technology's own plumber to rectify this as he is obviously very familiar with the system, but thanks for the offer.

Unfortunately we have lost contact with the original plumber, or we would be having a few words!

Thanks everyone for their input and suggestions - another example of what a great bunch of people PressF1ers are. :thumbs::thumbs::thumbs::thumbs:

pctek
11-05-2005, 06:57 PM
I'm not a plumber, but the valve is called an Ajax Valve, which is a pressure releasing valve, generally brassy in colour, with a rubber diaphragm in the centre.

They stopped making Ajax valves. They're now Nefa valves.

Jester
11-05-2005, 07:04 PM
They stopped making Ajax valves. They're now Nefa valves.

Probably to escape the liabilty claims. Wind the company up and start again with a new name :groan: