I have added a rad to my sealed system and since then half the rads in my house are not getting hot, basically those downstairs are cold. The pipe from the boiler goes to the upstairs rads first then down to the ground floor ones. I have tried shutting off all the rads upstairs, and then the downstairs ones do get a little warm. I wondered if its the pump. I opened the bleed screw on it and on speed positions 2 and 3 it spins, but on position 1 it does not, would having the bleed screw removed stop it spinning on position 1?
Boiler is a Heatline S30 compact about 10 years old. When draining the rads all seemed pretty clean.
(If I have to take the pump out to look at might as well change it)
Thanks
steve

Steve Jones wrote:
I have added a rad to my sealed system and since then half the rads in my house are not getting hot, basically those downstairs are cold. The pipe from the boiler goes to the upstairs rads first then down to the ground floor ones. I have tried shutting off all the rads upstairs, and then the downstairs ones do get a little warm. I wondered if its the pump. I opened the bleed screw on it and on speed positions 2 and 3 it spins, but on position 1 it does not, would having the bleed screw removed stop it spinning on position 1?
Boiler is a Heatline S30 compact about 10 years old. When draining the rads all seemed pretty clean.
(If I have to take the pump out to look at might as well change it)
Thanks
steve


I'd say it's an air lock problem.

On Monday, March 7, 2016 at 10:05:26 AM UTC, Capitol wrote:
Steve Jones wrote:
I have added a rad to my sealed system and since then half the rads in my house are not getting hot, basically those downstairs are cold. The pipe from the boiler goes to the upstairs rads first then down to the ground floor ones. I have tried shutting off all the rads upstairs, and then the downstairs ones do get a little warm. I wondered if its the pump. I opened the bleed screw on it and on speed positions 2 and 3 it spins, but on position 1 it does not, would having the bleed screw removed stop it spinning on position 1?
Boiler is a Heatline S30 compact about 10 years old. When draining the rads all seemed pretty clean.
(If I have to take the pump out to look at might as well change it)
Thanks
steve


I'd say it's an air lock problem.

How do I get rid of the airlock?
I have tried turning of all the upstairs rads anything else I could do?

Steve Jones wrote:
I have added a rad to my sealed system and since then half the rads in my house are not getting hot, basically those downstairs are cold. The pipe from the boiler goes to the upstairs rads first then down to the ground floor ones. I have tried shutting off all the rads upstairs, and then the downstairs ones do get a little warm. I wondered if its the pump. I opened the bleed screw on it and on speed positions 2 and 3 it spins, but on position 1 it does not, would having the bleed screw removed stop it spinning on position 1?
Boiler is a Heatline S30 compact about 10 years old. When draining the rads all seemed pretty clean.
(If I have to take the pump out to look at might as well change it)
Thanks
steve


I've managed to keep the same pump going for something like 25 years,
and it'll probably go for another 25. The insides will, naturally, get
coated in haematite, which will sometimes flake off, and sieze it.
Sometimes, it clears itself, but once I did need to dismantle it and
scrape it all out. If yours isn't turning on position 1, I'd assume it
was filling up with the nasty black stuff. The bleed screw shouldn't
actually be touching the shaft, I don't think. Mine doesn't.

When you shut off all the upstairs rads, did you leave all the
downstairs ones on at the same time? Until I put a drain cock on each
one (well worth doing), I found that when refilling, I had to turn on
each downstairs rad by itself in turn with the pump on 3. That was the
only way I could get it to blow the air down the pipes.

If you're going to take the pump off, have two new rubber washers ready.

When we first moved in our last house the heating system had the main pipes running of into the ceiling space with drop feeds to all the radiators on the ground floor and only one had a drain cock. Every time the system was drained down there was always some water in the downstairs pipes and radiators and always resulted in air locks on refill. The only solution is to put a drain cock on each radiator.

Richard

In article ,
Steve Jones wrote:
I have added a rad to my sealed system and since then half the rads in
my house are not getting hot, basically those downstairs are cold. The
pipe from the boiler goes to the upstairs rads first then down to the
ground floor ones. I have tried shutting off all the rads upstairs, and
then the downstairs ones do get a little warm. I wondered if its the
pump. I opened the bleed screw on it and on speed positions 2 and 3 it
spins, but on position 1 it does not, would having the bleed screw
removed stop it spinning on position 1? Boiler is a Heatline S30 compact
about 10 years old. When draining the rads all seemed pretty clean. (If
I have to take the pump out to look at might as well change it)

Water flow always takes the easiest route. If you are certain there are no
air locks, you need to partially close down the lockshields on the rad
which are getting hot to add resistance to that path. Note that lock
shields ain't linear - you'll probably end up with some only just cracking
open. Once you've got them all working, use an infra red thermometer to
get the correct flow on each and every one.

Most pumps have more than enough head for any domestic system. Unless
faulty, of course.

--
*A picture may be worth a thousand words, but it uses up a thousand times more memory.

Dave Plowman London SW
To e-mail, change noise into sound.

In article ,
"Dave Plowman (News)" writes:
In article ,
Steve Jones wrote:
I have added a rad to my sealed system and since then half the rads in
my house are not getting hot, basically those downstairs are cold. The
pipe from the boiler goes to the upstairs rads first then down to the
ground floor ones. I have tried shutting off all the rads upstairs, and
then the downstairs ones do get a little warm. I wondered if its the

Did you bleed all the radiators?
Did you check the tempertures only at the radiator top? Might be mostly air.

pump. I opened the bleed screw on it and on speed positions 2 and 3 it

If there's an air-lock in the pump, usually there's no flow and the
water boils in the boiler pretty quickly, and/or the boiler will
overheat and lockout. (Needless to say, this isn't good for the boiler.)

spins, but on position 1 it does not, would having the bleed screw
removed stop it spinning on position 1? Boiler is a Heatline S30 compact

No. There's usually a screwdriver slot on the shaft-end. With the pump
off, does the shaft turn very freely with a screwdriver?
It could be that the speed selector switch is faulty and not powering
the pump in position 1. What position was it originally in? It shouldn't
need changing.

about 10 years old. When draining the rads all seemed pretty clean. (If
I have to take the pump out to look at might as well change it)

Water flow always takes the easiest route. If you are certain there are no
air locks, you need to partially close down the lockshields on the rad
which are getting hot to add resistance to that path. Note that lock

If they worked correctly before, start by assuming they were correctly
set. It's probably just the new radiator which is not set correctly.
Start by turning that off (so system is just like it was before).
Does that make all the previously existing radiators work as they did
before? If not, you have some other problem which has to be fixed before
adjusting any of the lock-shield valves.

shields ain't linear - you'll probably end up with some only just cracking
open. Once you've got them all working, use an infra red thermometer to
get the correct flow on each and every one.

Most pumps have more than enough head for any domestic system. Unless
faulty, of course.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

On Monday, March 7, 2016 at 9:40:01 AM UTC, Steve Jones wrote:
I have added a rad to my sealed system and since then half the rads in my house are not getting hot, basically those downstairs are cold. The pipe from the boiler goes to the upstairs rads first then down to the ground floor ones. I have tried shutting off all the rads upstairs, and then the downstairs ones do get a little warm. I wondered if its the pump. I opened the bleed screw on it and on speed positions 2 and 3 it spins, but on position 1 it does not, would having the bleed screw removed stop it spinning on position 1?
Boiler is a Heatline S30 compact about 10 years old. When draining the rads all seemed pretty clean.
(If I have to take the pump out to look at might as well change it)
Thanks
steve

Turned all rads of again except the faulty ones and eventually all started working, so it was trapped air!!!