I have a Myson Apollo boiler and a conventional heating and Ho****er
system.

I have recently replaced the pump (myson 53) with a new one
(circulation pumps 53)after it failed but now have the following
problem.

When the system is running a small amount of water is coming out of
the overflow from the small black plastic tank in the loft. I was told
the pump may be set too low so I increased it to the second setting
but this only increased the flow of water so I put it back.

I have had it suggested that the thermostats in the boiler might have
gone and was wondering if anybody could tell me which. I understand
there is one for the return water temperature one for high and one for
low.

I am assuming it will be the return as the problem is still there
wether the boiler is set to high or low.

If anybody could clear this up for me or has another suggestion then I
would be grateful for any information.

When the system is running a small amount of water is coming out of
the overflow from the small black plastic tank in the loft. I was told
the pump may be set too low so I increased it to the second setting
but this only increased the flow of water so I put it back.

Slowing it down should reduce the flow. However, you might not be able to do
so if it is already on the slowest setting, or a slower setting doesn't get
everything hot enough. It probably happened when you changed the pump as it
was marginal before, but the new pump is just a little more powerful, enough
to pump over.

Quite frankly, systems with loft tanks are a complete pain in the arse. You
could fiddle around for years with air separators, moving pipework,
adjusting valves and pumps etc. Or you could rip it out and replace with a
proper sealed pressurised system that simply doesn't have all these
problems. There are other advantages too. It is much easier to bleed
radiators and flush the system. You get more storage space in the loft.
Leaks are less likely, as you can remove pipes from the freezing loft space.
Any leaks you do get are much less serious, as there is a limit to the
amount of water lost due to the manual fill arrangements.

To make the change, you just need a kit to upgrade, which will include a
pressure vessel, pressure relief valve, filling loop and pressure gauge. You
install these items, rip out the tank and you're done. It is a relatively
simple DIY plumbing job, similar in scope to plumbing in some new taps.

You would need to ensure that your existing system is compatible with sealed
operation. This basically means your boiler must have a safety cutout.

See:

http://www.plumbworld.co.uk/acb/show...=3479&CATID=17

(in case of wraps
http://makeashorterlink.com/?D51A35C67

The exact size you need depends on the size of your system. They have kits
from 8 litres to 24 litres. If you know the number and average size of the
radiators, you can calculate the minimum size required. Using one that is
too big isn't a problem. They vary from 40 to 50 quid including VAT
depending on size.

Christian.

In article ,
Christian McArdle wrote:
Quite frankly, systems with loft tanks are a complete pain in the arse.
You could fiddle around for years with air separators, moving pipework,
adjusting valves and pumps etc. Or you could rip it out and replace with
a proper sealed pressurised system that simply doesn't have all these
problems. There are other advantages too. It is much easier to bleed
radiators and flush the system. You get more storage space in the loft.
Leaks are less likely, as you can remove pipes from the freezing loft
space. Any leaks you do get are much less serious, as there is a limit
to the amount of water lost due to the manual fill arrangements.

While agreeing that if you actually need the space taken up by the header
tank a sealed system may make sense, header tanks worked perfectly well
for many years before them. Sometimes the simple way is actually the best.

--
*A journey of a thousand sites begins with a single click *

Dave Plowman London SW 12
RIP Acorn

While agreeing that if you actually need the space taken up by the
header tank a sealed system may make sense, header tanks worked
perfectly well for many years before them. Sometimes the simple way
is actually the best.

I see absolutely no advantages to open systems than these marginal ones:

1. Your boiler might require it.
2. You already have one and don't want to spend 50 quid upgrading.
3. Certain heat bank applications with common circulating water.

The advantages list goes on and on. Header tank systems rarely work well or
predictably, which is why sealed operation is now the norm.

Christian.

In article ,
Christian McArdle wrote:
I see absolutely no advantages to open systems than these marginal ones:

1. Your boiler might require it.
2. You already have one and don't want to spend 50 quid upgrading.

Only 50 quid? And how about the reliability of pressure vessels?

3. Certain heat bank applications with common circulating water.

The advantages list goes on and on. Header tank systems rarely work well
or predictably, which is why sealed operation is now the norm.

I reckon you're much exaggerating the problems with header tanks. And I'd
say sealed systems are popular for the same reasons as combis - they are
easier to install so make a larger profit for the plumber.

--
*Sorry, I don't date outside my species.

Dave Plowman London SW 12
RIP Acorn

Only 50 quid? And how about the reliability of pressure vessels?

That's the parts cost, provided you DIY. I reckon it would take me about 2
hours of my time in addition to affix a sealed system kit and cap off the
old pipes. This includes drilling a hole through the wall for the pressure
relief. The kit simply requires you to insert a T at convenient points in
the CH circuit and rising main and attach using compression joints.

Christian.

"mcslinger" wrote in message
om...
I have a Myson Apollo boiler and a conventional heating and Ho****er
system.

I have recently replaced the pump (myson 53) with a new one
(circulation pumps 53)after it failed but now have the following
problem.

When the system is running a small amount of water is coming out of
the overflow from the small black plastic tank in the loft. I was told
the pump may be set too low so I increased it to the second setting
but this only increased the flow of water so I put it back.

Increasing the pump rate would likely make the problem worse.

One explanation might be a blockage in the system, cause by sludge, or radiator
valves (including lockshields) and zone valves not opening enough.

Rasing the maximum height of the overflow pipe might well be a way of solving
the problem, so that the vertical distance between the highest point of the
overflow pipe and the level of the water in the tank is increased.

Michael Chare

"mcslinger" wrote in message
om...
I have a Myson Apollo boiler and a conventional heating and Ho****er
system.

I have recently replaced the pump (myson 53) with a new one
(circulation pumps 53)after it failed but now have the following
problem.

When the system is running a small amount of water is coming out of
the overflow from the small black plastic tank in the loft. I was told
the pump may be set too low so I increased it to the second setting
but this only increased the flow of water so I put it back.

I have had it suggested that the thermostats in the boiler might have
gone and was wondering if anybody could tell me which. I understand
there is one for the return water temperature one for high and one for
low.

I am assuming it will be the return as the problem is still there
wether the boiler is set to high or low.

If anybody could clear this up for me or has another suggestion then I
would be grateful for any information.

First of all do you mean the overflow (which carries water away from the
tank to an open pipe discharging somewhere outside the house where it
is|should be visible?

Or do you mean the vent pipe which is roughly like the crook of a walking
stick and opens over the tank itself?

From the sysmptoms you describe it sounds to me (and everyone else who's
replied to this thread) like the latter. If it is then apart from making
sure the top of the walking-stick section is as high as possible above the
tank and the water level in the tank when cold is only about 2-3", you
should check that the outlet (feed) pipe from the tank and the vent pipe
both join the main pipework close together - less than 6" apart.

"John Stumbles" wrote in message ...
"mcslinger" wrote in message
om...
I have a Myson Apollo boiler and a conventional heating and Ho****er
system.

I have recently replaced the pump (myson 53) with a new one
(circulation pumps 53)after it failed but now have the following
problem.

When the system is running a small amount of water is coming out of
the overflow from the small black plastic tank in the loft. I was told
the pump may be set too low so I increased it to the second setting
but this only increased the flow of water so I put it back.

I have had it suggested that the thermostats in the boiler might have
gone and was wondering if anybody could tell me which. I understand
there is one for the return water temperature one for high and one for
low.

I am assuming it will be the return as the problem is still there
wether the boiler is set to high or low.

If anybody could clear this up for me or has another suggestion then I
would be grateful for any information.

First of all do you mean the overflow (which carries water away from the
tank to an open pipe discharging somewhere outside the house where it
is|should be visible?

Yes I mean the pipe coming of the small tank to the outside of my
house where it is dripping down the wall.

Or do you mean the vent pipe which is roughly like the crook of a walking
stick and opens over the tank itself?

From the sysmptoms you describe it sounds to me (and everyone else who's
replied to this thread) like the latter. If it is then apart from making
sure the top of the walking-stick section is as high as possible above the
tank and the water level in the tank when cold is only about 2-3", you
should check that the outlet (feed) pipe from the tank and the vent pipe
both join the main pipework close together - less than 6" apart.

In article ,
mcslinger wrote:
Yes I mean the pipe coming of the small tank to the outside of my
house where it is dripping down the wall.

Then that's got nothing to do with the pump.

Change the washer in the ball valve.

--
He who laughs last, thinks slowest.

Dave Plowman London SW 12
RIP Acorn