Ideal Icos knocking - low water pressure?

pjblink · Posted: Wed Sep 30, 2009 10:00 pm

Hey guys,

I've recently moved into a coach house (all on one floor), and we immediately are having trouble with the central heating. Some of the radiators were heating up well and proper, but others weren't. I switched off the ones that were heating up, and the others did indeed heat up.

We've only been in a few days, and the boiler is knocking shortly after lighting up. A video is uplolading, i'll post soon...

Now to my very basic knowledge, this seems to point towards low pressure in the system? I am trying, but can't for the life of me find a pressure gauge. I've taken the front off the boiler, been up in the loft etc, all around the tank - but can't find one. Nor can i seem to find a loop to re-pressurise the system. Under the sink is a large mix up of wires and tubes from the washing machine, i havn't yet decoded these.

The other issue i have is that the central heating (havn't set the water to heat up yet) seems to also be heating up the water. I set the tank thermostat at 50C and the water is getting well above that. The motorised valve (3 way - Danfoss) doesn't seem to have any "spring" in it. When i moved in, it was set at manual. I can switch it to auto, but there is nothing to pull it in that direction... It also seems to be fitted upside down, on the side of the unit it points down "A - Heating" and up "B - Hot Water". On the piping it's fitted to, A is up into the ceiling, and B is down, into the tank.

The only other thing is that there is a pipe going up, with a white knurled knob on the end. When i undo this, i can read a gauge of bar readings, 0.6,0.5,0.4 etc. What is this for?

Any thoughts on helping us?

Cheers, Patrick

kevplumb · Posted: Wed Sep 30, 2009 10:07 pm

Quote:

The only other thing is that there is a pipe going up, with a white knurled knob on the end. When i undo this, i can read a gauge of bar readings, 0.6,0.5,0.4 etc. What is this for?

auto bypass valve

fill loop

davebgas · Posted: Wed Sep 30, 2009 10:08 pm

Tank In loft = open system and not pressurised. Hence no gauge. Check system has water in it and the pump speed is on full.
3port valve set up is A to rads, B to cylinder. But should be set to auto as manual is used for filling and draining.
Just to clarify though, this is an ICOS? And you definately have tanks in the loft with a ballcock? Only ask as there are 2 variatants of the Icos, a system or heat only.

kevindgas · Posted: Wed Sep 30, 2009 10:32 pm

davebgas wrote:

Just to clarify though, this is an ICOS? And you definately have tanks in the loft with a ballcock? Only ask as there are 2 variatants of the Icos, a system or heat only.

and they are both s****!

pjblink · Posted: Wed Sep 30, 2009 10:34 pm

Cheers for the responses guys

Definately an Icos. Tanks in the roof, not sure on ballcock, didn't delve too deep. A large bath sized tank on it's side, as well as a small cistern sized tank beside it.

Pump speed was on 2/3, i put it up to 3/3 which has made no difference (can hear speed difference in pump though).

How do i check system has water in it? Bled all the radiaters etc, no air in there. How does the auto bypass valve work, and how should it be set?

Is the fact that the arrows on the mechanical valve plastic point in opposite directions to that on the pipes it's fitted to an issue?

pjblink · Posted: Wed Sep 30, 2009 11:06 pm

Video of boiler in action can be seen here:

And this is the mechanical valve:

gas4you · Posted: Thu Oct 01, 2009 7:05 am

No circulation and the boiler is over heating.

davebgas · Posted: Thu Oct 01, 2009 8:58 am

Check the pump is running ok

shambolic · Posted: Thu Oct 01, 2009 2:28 pm

Defo overheating either a blockage, airlock, or pump not working.
Advisable not to try and use as you may burst the heat exchanger !

izzy eckerslike · Posted: Thu Oct 01, 2009 4:11 pm

Exactly what we had after our spanky new icos HE24 was fitted by warmfront, it only did it on hot water only not with heating on. The clonking lasted about 3 mintutes then all went silent

It is only air & sounds worse than it is but in our case after two visits they discovered it was the gate valve on the return pipe from the hot water cylinder closed off to much. Instantly cured by opening the valve a bit more

davebgas · Posted: Thu Oct 01, 2009 4:18 pm

Do NOT assume it's just air!!! Check the pump!!! From the picture this is not a new ICOS as the user control is different. Listen to shambolic as he works for Ideal!!!

petit_pablo · Posted: Thu Oct 01, 2009 4:42 pm

When you bled the radiators did water come out forcibly / dribble out or no air or water?

There could well be a blockage in the cold feed if the water just dribbled out or nothing came out.

See its been abused by BG at somepoint judging by the stickers on boiler!

gas4you · Posted: Thu Oct 01, 2009 6:55 pm

This is the original M3080

shambolic · Posted: Thu Oct 01, 2009 9:34 pm

As said by a couple of observant peeps on here this boiler is an m3080 original icos and is probably seven years old!!
(lasted this long FFS) Hope this satisfies you lot

But it will be an external fault of air, pump, or circulation probs but get someone to check as it could cause irreprable(sp) damage to boiler also get it checked and serviced including sump cleaned electrodes checke insulation panels condense checked etc if not yo could be in for more trouble

shambolic · Posted: Thu Oct 01, 2009 9:43 pm

izzy eckerslike wrote:

Exactly what we had after our spanky new icos HE24 was fitted by warmfront, it only did it on hot water only not with heating on. The clonking lasted about 3 mintutes then all went silent

It is only air & sounds worse than it is but in our case after two visits they discovered it was the gate valve on the return pipe from the hot water cylinder closed off to much. Instantly cured by opening the valve a bit more

Had the same today with a He 36 mexico fitted to a n old system with an oil fired boiler. installer left the pump and motorised valves on the return and also left the old 22 mm primaries!!!!
Cust has had them out 10 times in the last 10 months due to noise and other problems.
i went today and spent the time getting to know the system and more importantly getting to knwo the customers.
Now TBH this was not a boiler problem but it looked bad as fault only occured since our boiler fitted(no pros with old oil boiler)

On questioning cutomer they had a noise problem on and of and the installer came out to sort several times.
They have not had any noise since last installer call out but they also have had poor HW and no heat to lounge which has 2 fan heaters.
the installer had solved the noise problem by turning the boiler stat to 42 degrees!!!
Bingo no more overheating but **** all heat and hw!!!
I despair sometimes
so my advice was boiler ok But 36 kw through 22mm primaries disnae really work please read instructions