Expansion tank - Looks like I've got a problem. Please Help

[bananas and custard]

Hi
This is my first house with central heating and I don't know whats right and what's not.
In the attic the curved pipe over the little expansion tank is pouring water into the tank.
Does this mean the water is only going round that bit and there is a blockage or should this be running all the while. The radiators are warm not hot and all the dials on the radiators are on max.

 

[bananas and custard]

I'm also concerned about the large quantity of steam rising off the tank.
Just found out the pump has different speeds and it is on 3. If I change it to 1 the water stops and it's a trickle on 2. Have left it on 3 but some rads don't get hot just warm.

 

[oilman]

You probably have a blockage, and maybe a thermostat problem. Turn the pump to 1 until you have it sorted. You may need to turn the boiler off if it makes banging noises, and the header tank should be cleaned out.

 

[bananas and custard]

So is it a problem that the water is running in the tank like this. Should the pipe over the tank not be running?

A blockage, why and where? I know you're not here to see it but any ideas what it could be?

 

[PIPERPETE]

The expansion pipe has been fitted at the wrong side of the pump, check that the expansion pipe thats blowing over is behind the pump not in front of it.

 

[bananas and custard]

Pump pipes are horizontal.

6 inches away from pump towards boiler is a joint with the expanion pipe over the tank.

18 inches the other side of the pump is another joint where the pipe divides to two motor valves.

In a word should the expansion pipe be running or not?

If it's a blockage what is it likely to be?

 

[Softus]

Water running out of the vent is not the way it's designed to be, so it's a symptom of problem, rather than a problem per se.

One common point of a blockage is at the junction of the cold feed into the pumped circuit. This can be exacerbated by incorrect installation - in the direction of flow, the sequence should be vent, cold feed, pump. If the vent is after the cold vent then there's a risk of pulling in air, and if the vent is after the pump then there's a risk of "pumping over".

The chances are that you're at the beginning of a medium length road leading from an unhealthy system to a healthy one. You may wish to consider the virtues of leaving the work until the spring, but you can mitigate the problem in the meantime.

However, if your system is pumping over, then you may get away with just cleaning it for now. I would do this by draining the water out of the system (with the boiler and pump turned off) until the F&E cistern is empty, then drain the same amount again, then add a cleaner to the cistern and re-fill. You'll need to shut off the cold feed to the F&E while doing this - tying up the ball valve will do if you have no service valve ro stop cock.

Run the system for a couple of weeks in this state - ensure that each radiator gets nice and hot for some of that time. When you drain down after all of this (do it HOT) then the water should contain much of the muck that's blocking your system. You can then add an inhibitor, and refill, and wait until the spring.

BTW, the forum contains information about about blockages, and sludge, and draining, and inhibitors, and pumping over, and blockages, and sludge....

 

[bananas and custard]

Will check the exact pipe layout later Softus, thanks for the info.

Just seen too that the boiler dial is on maximum, would it help the pump over in the expansion tank if I turned it down?

Used the website that was in someone elses post today about pump speeds and it says my pump should be on speed 3.

 

[Softus]

Just seen too that the boiler dial is on maximum, would it help the pump over in the expansion tank if I turned it down?

I very much doubt it - the boiler setting determines the temperature of water leaving the boiler (at a given flow rate). Turning this down will just reduce (a) the temperature of the water at the radiators, and (b) the time it takes for the system to heat up the water in the cylinder.

Used the website that was in someone elses post today about pump speeds and it says my pump should be on speed 3.

I don't know what topic you were reading, or what reason was behind the advice that you read there, but pump speed is determined, mainly, by the resistance to flow throughout the system. The objective is to achieve the optimum temperature difference between water leaving and returning to the boiler.

Generally, I put pumps on speed "2" unless there's a reason to do otherwise.

 

[bananas and custard]

Softus

I have just been up the loft again and followed all the pipes.

The pipe comes from the boiler and T's to the pump over pipe, then 6 inches later is the feed pipe from the tank, then 6 inches after that is the pump.

After the pump the pipe divides to the two motor valves.

Sounds like it's plumbed the way you said it should be.

I have turned the pump down to speed 2 but it's still pumping over, just not as fast.

Also, I've been to B&Q and the man there said the best cleaner was Fernox Heavy Duty Restorer. That's in now, drained all the water out first so it's in there with fresh water. How long can I leave this in before I have to empty it?

As for the pump speeds it was a post on this forum, here's the topic


//www.diynot.com/forums/viewtopic.php?t=37420

with a link to this website:

http://www.bpma.org.uk/wilo/index2.htm

Thanks for your help, all advice gratefully received.

 

[bananas and custard]

Heating been running for a few hours now with the pump on 2.

Sure there is less water from expansion pipe but the house is colder too.

Any ideas please.

 

[meldrew's_mate]

Have you checked that the pump is pumping the correct way?
There is normally an arrow on the body showing the direction.
From the descriptions given it seems you have a standard fully pumped system with the pump on the flow, so pumping over shouldn't happen unless the pump is the wrong way around.
What make/output is your boiler? Does it fire continuously when the system is warming up, or in short bursts?

 

[bananas and custard]

Boiler runs continous while warming up. It is Ideal W, no numbers on it but inside the door it lists about 6 different boilers and I don't know what I've got.

Can't see an arrow on the pump, have to practically stand on my head to get to it.

If you look at this picture of one it would be as though the boiler, expansion then feed were below the pump and valves, rads etc above it.

 

[bananas and custard]

I know the picture in previous post would explain itself to most people but just found the arrow and it is pumping in the right direction.

 

[Elephant_Guy]

I have exactly the same problem as bananas and custard.
Boiling water discharging into the expansion tank creating lots of steam and condensation in attic but no water coming out of the overflow pipe.
Expansion pipe is on the correct side of the pump and system cleaned out with Fernox only 6 months ago.

I would love to know the answer to the problem that bananas and custard and myself appear to be suffering from.......