has anyone any experience?
I bought these to solve a problem regarding noise and frequency of the
need to bleed a CH system.
They seem fairly ineffectual, blowing through the things prior to
fitting didnt seem to cofirm an airflow, but the noise from the system
and the amount of "air"? expelled seems to have increased.
If anything It would seem that they draw air in.
On 14/05/2018 23:18, Archibald Tarquin Blenkinsopp wrote:
Yes, not impressed.
When first fitted to a drained down system they worked well and as shown
in the advertising Youtube videos.
I assume that these have a membain that expands when wet to seal the
valve. In my experience once sealed they never seem to open again.
When draining down the system subsequently these valves remain closed,
possibly because they take years to dry out in ambient temperatures, so
that on refilling a system a day or two later they don't work.
On an old system refilling a system may also disturb the sludge in the
radiator and this gets into that pin-hole in the valve. When I removed
one it wasn't clean!
Or they are stuck closed and the air is just building up as you are
bleeding less often in the mistaken belief that the Alladin valves are
I note that Allidin do replacement cartridges for their more expensive
look-alike professional devices which may indicate a fairly low life
On Tue, 15 May 2018 01:36:58 -0700 (PDT), firstname.lastname@example.org wrote:
I always had a slight problem, I installed the basic unit
myself, but had a heating company fit a boiler/ stove.
The back boiler came out and so did the HW tank.
They also removed my 3 port valve, Honeywell and instead of taking the
feed to the radiators from the delivery side of the pump, the
radiators go to the suction. Frrom that point the air became
Recently the air in the system has increased despite using generous
amounts of inhibitor, I suspect a leak, but I didn't get around to
checking whether the gas is Hydrogen. When the pump kicks in, it
sounds like a mini waterfall for a few seconds. I have an auto vent
which I do not like to leave unattended in case the seal gets
I can isolate the rads, so I will build a pressure tester. I assume
theres nothing on the market for DIY use?
Based on what you have said, given the timing, it does sound like there may well be a leak where they removed the valve and it is sucking in air.
What type of system do you have? Do you have a header tank for topping up the CH system or is it a pressurised system?
Assume you have fully bled the system and it continues to suck in air?
On Tue, 15 May 2018 02:50:33 -0700 (PDT), email@example.com wrote:
Thanks for the interest.
Yes the system has a header tank, I am not sure if I "fully" bled the
system, but it has been a couple of years since the upgrade and the
problem has actually worsened.
The system is in a bungalow, so each rad is dropped from the loft,
Ideally I should have used a level for setting a high spot, but space
was very restricted, the roof has a shallow angle.
I stuck a auto bleed valve at what seemed like the highest point.
I put isolation valves on the feed and return to the rads, so I think
I will drain the system, flush it and pessure test it with air.
I have put on a few stone since the initial installation, so listening
for leaks will take some intensive low calorie preparation :-(
The problem is compounded by the fact that I only use the house
intermittently, I cannot inspect tank levels since the introduction of
insulation and due to the acidic nature of the supplied water, I have
kept the mains water off when not present.
I have checked the pH of the incoming water and for the last year or
so the company seem to have got their act in order and the pH is at
7.0, so I would doubt that the water is reacting with the inhibitor.
On the assumption that there isn't a fundamental design issue with your sys
tem I would assume the more obvious reasons and rule them out first. When y
ou are next there I would try the following
1. Check the header tank to ensure it has water in it and the ballcock hasn
't stuck and is working correctly (likely to be the cause I am guessing )
2. If that is ok. With the hot water and heating off, bleed all the radiato
rs. Check that the header is filling correctly to ensure it never goes belo
w the top of the feed pipe during this process.
3. If this doesn't fix it and / or as an extra test, put something over the
vent pipe (ie the one that dumps any expanded water into the header tank)
so you can tell whether water is being pumped out of it or air sucked in. C
ould use a cloth for the former. For the latter you could seal a bit of bal
loon or similar over the end and you would see it getting sucked in or susp
end a tub of water such that the end is submerged. If it is sucking water w
ill be sucked out of the tub.
If none of this works post the results here and we could go to phase 2
On Tue, 15 May 2018 05:27:37 -0700 (PDT), firstname.lastname@example.org wrote:
Thanks. To be honest the header tank would be the first point of call.
I replaced the "cooked" ballcock float about 5 yrs back.
It was a very difficult squeeze. I am now 6 stone heavier.
I'm just going to have to replace the perished tyres on my old Raleigh
racer first :-)
It will take months or a thin heating eng to inspoect the header.
I am confident that the header is working as I drained and removed a
couple of radiators to fit the alladdin valves and check the sludge
levels. I could hear the tank filling.
I did actually think of putting a resevoir on the incoming feed, just
to make sure that there was a visible supply to the CH.
In the meantime the simplest most practical option seems to be to
pressure test what I can get to and in a worst case scenario,
introduce additional water to the system.
I did actually find an unsoldered union last year, strange but after
all the heating and cooling, I only became aware when isolating an
If the header tank is working fine (is filling) then it will add all the wa
ter needed. When you refilled the rads, it may be that you were using water
to replace the air quicker than the tank could provide it. Either way, I t
hink the next step is to bleed all the rads in the manner I suggested above
When you say pressure testing bits of the system, how would you do this if
you can't seal off the vent and header tank?
On Tue, 15 May 2018 10:27:14 -0700 (PDT), email@example.com wrote:
I can valve off the header, I don't think the vent has a valve though.
The rads are in a circuit valved at the airing cupboard.
I have bled all the rads on numerous occasions, but the pipework drops
down from the loft. I also have a manual bleed valve and an auto bleed
in the loft. The procedure was to turn the pump off, minimal heating
running i.e let the stove die down, open auto vent, open manual vent,
Run pump, repeat venting, run pump, repeat venting.
At this point there would be virtually no gas in the system.
Basically if I have an air leak, the most likely place is in the loft
where the rads ar fed from. this has the largest number of compression
fittings as I put isolation valves on all the feeds.
I would find it easy to manufacture a fitting to introduce air, this
would have the advantage of being more searching than water and should
enable identification using soap spray.
The main part of the system is in the airing cupboard so this should
not be too difficult to check either. To adopt the air detection
technique would need a bit of thought regarding blanking though and
I'm not sure what the seals on the pump are rated at.
Of course I am assuming that a leak is the problem!
I still cannot understand why the stove installer connected the
suction of the pump to the rad circuit though. It seems that most of
the problems stemmed from that action. I originally had the rads and
tank coil fed from the delivery side of the pump, additionally, I had
a three port valve to ensure that priority was given to the hot water.
The removal of this did not in actual fact make a lot of difference
Not sure what you mean by suction side but... If the pump change timing con
curred with the problems, wonder if the change has resulted in it sucking i
n air via the vent pipe. I had this problem once when I temporarily reduced
the number of rads on my circuit. The pump was then too strong. I turned i
t down to the lowest setting and all sorted. If your pump has variable spee
d that would be a simple test.
On 15/05/2018 17:03, Archibald Tarquin Blenkinsopp wrote:
Are you sure it is not pumping over? If the pump is circulating the
water by way of the header tank it will be aerated water getting into
your system. Perhaps the header tank, or the expansion pipe outlet, is
not high enough for your pump speed, especially as you indicate the tank
may be close to the high point of the pipes in the loft. If your pump is
adjusting dependent on load perhaps pumping over only occurs occasionally.
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