Replacement for Myson Unit 5 ch pump
 

Pump has been a bit weak ever since we bought the house. Now getting
noisier and less effective.

Ideas for a replacement please.

House is 3 bed detached reasonably well insulated in Essex. 2 storeys
about 500 sq ft each.

All pumped system. Boiler is a 24HXI, usual 25mm pipes to ordinary rads.

We get some horrible airlocks so something that is easily bled and with
a bit of oomph would be good.

As usual it is in a position where it would be difficult to change the
pipework. Prefer one that would fit the same as the Myson.

TIA for any advice.

Replacement for Myson Unit 5 ch pump
 

On 30 Mar, 17:00, Invisible Man wrote:
Pump has been a bit weak ever since we bought the house. Now getting
noisier and less effective.

Ideas for a replacement please.

House is 3 bed detached reasonably well insulated in Essex. 2 storeys
about 500 sq ft each.

All pumped system. Boiler is a 24HXI, usual 25mm pipes to ordinary rads.

We get some horrible airlocks so something that is easily bled and with
a bit of oomph would be good.

As usual it is in a position where it would be difficult to change the
pipework. Prefer one that would fit the same as the Myson.

TIA for any advice.

Why do you suffer repeated airlocks? Once the system is settled you
should not get any.

Replacement for Myson Unit 5 ch pump
 

On 30/03/2010 17:07, cynic wrote:
On 30 Mar, 17:00, Invisible wrote:
Pump has been a bit weak ever since we bought the house. Now getting
noisier and less effective.

Ideas for a replacement please.

House is 3 bed detached reasonably well insulated in Essex. 2 storeys
about 500 sq ft each.

All pumped system. Boiler is a 24HXI, usual 25mm pipes to ordinary rads.

We get some horrible airlocks so something that is easily bled and with
a bit of oomph would be good.

As usual it is in a position where it would be difficult to change the
pipework. Prefer one that would fit the same as the Myson.

TIA for any advice.

Why do you suffer repeated airlocks? Once the system is settled you
should not get any.

Just whenever I do anything. Eg. turn off radiator, drain rad down and
remove it to decorate. Turn off system, reconnect rad. open 1 valve and
allow air to escape from bleed valve until water appears. Turn system
back on and airlock causes boiler to overheat and cut out. Never had a
place like it.
We have done a lot to this house in the 3.5 years we have been here and
it is a real pain.

Replacement for Myson Unit 5 ch pump
 

On 30 Mar, 17:44, Invisible Man wrote:
On 30/03/2010 17:07, cynic wrote:





On 30 Mar, 17:00, Invisible *wrote:
Pump has been a bit weak ever since we bought the house. Now getting
noisier and less effective.

Ideas for a replacement please.

House is 3 bed detached reasonably well insulated in Essex. 2 storeys
about 500 sq ft each.

All pumped system. Boiler is a 24HXI, usual 25mm pipes to ordinary rads.

We get some horrible airlocks so something that is easily bled and with
a bit of oomph would be good.

As usual it is in a position where it would be difficult to change the
pipework. Prefer one that would fit the same as the Myson.

TIA for any advice.

Why do you suffer repeated airlocks? Once the system is settled you
should not get any.

Just whenever I do anything. Eg. turn off radiator, drain rad down and
remove it to decorate. Turn off system, reconnect rad. open 1 valve and
allow air to escape from bleed valve until water appears. Turn system
back on and airlock causes boiler to overheat and cut out. Never had a
place like it.
We have done a lot to this house in the 3.5 years we have been here and
it is a real pain.- Hide quoted text -

- Show quoted text -

That sounds as though you have a more fundamental problem which needs
sorting out before you go throwing money at replacing the pump.
For a start do you have an open vented or sealed system? if open
vented does the pump "push" the water around from the neutral point or
does it "pull" it back from the rads? If sealed does the pressure
remain above about 0-8 bar when cold? Do you have any kind of
corrosion inhibitor in the water?
Just a slight modification to suggest to your refilling procedure
after refitting a radiator - when in place and tightened up (and pump
switched off) open the rad vent and one of the rad valves for a few
seconds, close the rad valve and open the other so you are expelling
air from both the inlet and outlet connections as you refill. The
amount of air in one connection should not cause the problems you
describe but it does at least ensure you clear both.

Replacement for Myson Unit 5 ch pump
 

On 30/03/2010 20:49, cynic wrote:
On 30 Mar, 17:44, Invisible wrote:
On 30/03/2010 17:07, cynic wrote:





On 30 Mar, 17:00, Invisible wrote:
Pump has been a bit weak ever since we bought the house. Now getting
noisier and less effective.

Ideas for a replacement please.

House is 3 bed detached reasonably well insulated in Essex. 2 storeys
about 500 sq ft each.

All pumped system. Boiler is a 24HXI, usual 25mm pipes to ordinary rads.

We get some horrible airlocks so something that is easily bled and with
a bit of oomph would be good.

As usual it is in a position where it would be difficult to change the
pipework. Prefer one that would fit the same as the Myson.

TIA for any advice.

Why do you suffer repeated airlocks? Once the system is settled you
should not get any.

Just whenever I do anything. Eg. turn off radiator, drain rad down and
remove it to decorate. Turn off system, reconnect rad. open 1 valve and
allow air to escape from bleed valve until water appears. Turn system
back on and airlock causes boiler to overheat and cut out. Never had a
place like it.
We have done a lot to this house in the 3.5 years we have been here and
it is a real pain.- Hide quoted text -

- Show quoted text -

That sounds as though you have a more fundamental problem which needs
sorting out before you go throwing money at replacing the pump.
For a start do you have an open vented or sealed system? if open
vented does the pump "push" the water around from the neutral point or
does it "pull" it back from the rads? If sealed does the pressure
remain above about 0-8 bar when cold? Do you have any kind of
corrosion inhibitor in the water?
Just a slight modification to suggest to your refilling procedure
after refitting a radiator - when in place and tightened up (and pump
switched off) open the rad vent and one of the rad valves for a few
seconds, close the rad valve and open the other so you are expelling
air from both the inlet and outlet connections as you refill. The
amount of air in one connection should not cause the problems you
describe but it does at least ensure you clear both.

Thanks for the idea on clearing rads from both ends - one at a time.

System is open vented, pump pushes water from boiler to 3 way valve to
rads and hw cylinder.

Fernox in the system. System is pretty clean. The system does not
collect air once it is all out. No reason to believe air is sucked from
the overflow. the pump is getting noisy and the flow rate is not as
great as I would like.

Replacement for Myson Unit 5 ch pump
 

On 30 Mar, 21:58, Invisible Man wrote:
On 30/03/2010 20:49, cynic wrote:





On 30 Mar, 17:44, Invisible *wrote:
On 30/03/2010 17:07, cynic wrote:

On 30 Mar, 17:00, Invisible * *wrote:
Pump has been a bit weak ever since we bought the house. Now getting
noisier and less effective.

Ideas for a replacement please.

House is 3 bed detached reasonably well insulated in Essex. 2 storeys
about 500 sq ft each.

All pumped system. Boiler is a 24HXI, usual 25mm pipes to ordinary rads.

We get some horrible airlocks so something that is easily bled and with
a bit of oomph would be good.

As usual it is in a position where it would be difficult to change the
pipework. Prefer one that would fit the same as the Myson.

TIA for any advice.

Why do you suffer repeated airlocks? Once the system is settled you
should not get any.

Just whenever I do anything. Eg. turn off radiator, drain rad down and
remove it to decorate. Turn off system, reconnect rad. open 1 valve and
allow air to escape from bleed valve until water appears. Turn system
back on and airlock causes boiler to overheat and cut out. Never had a
place like it.
We have done a lot to this house in the 3.5 years we have been here and
it is a real pain.- Hide quoted text -

- Show quoted text -

That sounds as though you have a more fundamental problem which needs
sorting out before you go throwing money at replacing the pump.
For a start do you have an open vented or sealed system? if open
vented does the pump "push" the water around from the neutral point or
does it "pull" it back from the rads? If sealed does the pressure
remain above about 0-8 bar when cold? Do you have any kind of
corrosion inhibitor in the water?
Just a slight modification to suggest to your refilling procedure
after refitting a radiator - when in place and tightened up (and pump
switched off) open the rad vent and one of the rad valves for a few
seconds, close the rad valve and open the other so you are expelling
air from both the inlet and outlet connections as you refill. The
amount of air in one connection should not cause the problems you
describe but it does at least ensure you clear both.

Thanks for the idea on clearing rads from both ends - one at a time.

System is open vented, pump pushes water from boiler to 3 way valve to
rads and hw cylinder.

Fernox in the system. System is pretty clean. The system does not
collect air once it is all out. No reason to believe air is sucked from
the overflow. the pump is getting noisy and the flow rate is not as
great as I would like.- Hide quoted text -

- Show quoted text -

Ok - it sounded as though you had a continuous air problem but this is
not the case. My reccomendation would be to fit a Grundfoss pump and
your local plumb centre or other stockist will have a chart to say
which model would have the right performance. If the replacement is a
different connection you should make the modification as it will be a
once only exercise

Replacement for Myson Unit 5 ch pump
 

On 31/03/2010 13:00, cynic wrote:
On 30 Mar, 21:58, Invisible wrote:
On 30/03/2010 20:49, cynic wrote:





On 30 Mar, 17:44, Invisible wrote:
On 30/03/2010 17:07, cynic wrote:

On 30 Mar, 17:00, Invisible wrote:
Pump has been a bit weak ever since we bought the house. Now getting
noisier and less effective.

Ideas for a replacement please.

House is 3 bed detached reasonably well insulated in Essex. 2 storeys
about 500 sq ft each.

All pumped system. Boiler is a 24HXI, usual 25mm pipes to ordinary rads.

We get some horrible airlocks so something that is easily bled and with
a bit of oomph would be good.

As usual it is in a position where it would be difficult to change the
pipework. Prefer one that would fit the same as the Myson.

TIA for any advice.

Why do you suffer repeated airlocks? Once the system is settled you
should not get any.

Just whenever I do anything. Eg. turn off radiator, drain rad down and
remove it to decorate. Turn off system, reconnect rad. open 1 valve and
allow air to escape from bleed valve until water appears. Turn system
back on and airlock causes boiler to overheat and cut out. Never had a
place like it.
We have done a lot to this house in the 3.5 years we have been here and
it is a real pain.- Hide quoted text -

- Show quoted text -

That sounds as though you have a more fundamental problem which needs
sorting out before you go throwing money at replacing the pump.
For a start do you have an open vented or sealed system? if open
vented does the pump "push" the water around from the neutral point or
does it "pull" it back from the rads? If sealed does the pressure
remain above about 0-8 bar when cold? Do you have any kind of
corrosion inhibitor in the water?
Just a slight modification to suggest to your refilling procedure
after refitting a radiator - when in place and tightened up (and pump
switched off) open the rad vent and one of the rad valves for a few
seconds, close the rad valve and open the other so you are expelling
air from both the inlet and outlet connections as you refill. The
amount of air in one connection should not cause the problems you
describe but it does at least ensure you clear both.

Thanks for the idea on clearing rads from both ends - one at a time.

System is open vented, pump pushes water from boiler to 3 way valve to
rads and hw cylinder.

Fernox in the system. System is pretty clean. The system does not
collect air once it is all out. No reason to believe air is sucked from
the overflow. the pump is getting noisy and the flow rate is not as
great as I would like.- Hide quoted text -

- Show quoted text -

Ok - it sounded as though you had a continuous air problem but this is
not the case. My reccomendation would be to fit a Grundfoss pump and
your local plumb centre or other stockist will have a chart to say
which model would have the right performance. If the replacement is a
different connection you should make the modification as it will be a
once only exercise

Thanks for your help. The noise and vibration from the old pump woke me
up this morning. I could no doubt cut the vibration but previous
experience suggests it is not going to last forever so I will do it when
it suits me rather than when it finally stops at an inconvenient moment.

Outcome Replacement for Myson Unit 5 ch pump
 

On 31/03/2010 13:16, Invisible Man wrote:
On 31/03/2010 13:00, cynic wrote:
On 30 Mar, 21:58, Invisible wrote:
On 30/03/2010 20:49, cynic wrote:





On 30 Mar, 17:44, Invisible wrote:
On 30/03/2010 17:07, cynic wrote:

On 30 Mar, 17:00, Invisible wrote:
Pump has been a bit weak ever since we bought the house. Now getting
noisier and less effective.

Ideas for a replacement please.

House is 3 bed detached reasonably well insulated in Essex. 2
storeys
about 500 sq ft each.

All pumped system. Boiler is a 24HXI, usual 25mm pipes to
ordinary rads.

We get some horrible airlocks so something that is easily bled
and with
a bit of oomph would be good.

As usual it is in a position where it would be difficult to
change the
pipework. Prefer one that would fit the same as the Myson.

TIA for any advice.

Why do you suffer repeated airlocks? Once the system is settled you
should not get any.

Just whenever I do anything. Eg. turn off radiator, drain rad down and
remove it to decorate. Turn off system, reconnect rad. open 1 valve
and
allow air to escape from bleed valve until water appears. Turn system
back on and airlock causes boiler to overheat and cut out. Never had a
place like it.
We have done a lot to this house in the 3.5 years we have been here
and
it is a real pain.- Hide quoted text -

- Show quoted text -

That sounds as though you have a more fundamental problem which needs
sorting out before you go throwing money at replacing the pump.
For a start do you have an open vented or sealed system? if open
vented does the pump "push" the water around from the neutral point or
does it "pull" it back from the rads? If sealed does the pressure
remain above about 0-8 bar when cold? Do you have any kind of
corrosion inhibitor in the water?
Just a slight modification to suggest to your refilling procedure
after refitting a radiator - when in place and tightened up (and pump
switched off) open the rad vent and one of the rad valves for a few
seconds, close the rad valve and open the other so you are expelling
air from both the inlet and outlet connections as you refill. The
amount of air in one connection should not cause the problems you
describe but it does at least ensure you clear both.

Thanks for the idea on clearing rads from both ends - one at a time.

System is open vented, pump pushes water from boiler to 3 way valve to
rads and hw cylinder.

Fernox in the system. System is pretty clean. The system does not
collect air once it is all out. No reason to believe air is sucked from
the overflow. the pump is getting noisy and the flow rate is not as
great as I would like.- Hide quoted text -

- Show quoted text -

Ok - it sounded as though you had a continuous air problem but this is
not the case. My reccomendation would be to fit a Grundfoss pump and
your local plumb centre or other stockist will have a chart to say
which model would have the right performance. If the replacement is a
different connection you should make the modification as it will be a
once only exercise

Thanks for your help. The noise and vibration from the old pump woke me
up this morning. I could no doubt cut the vibration but previous
experience suggests it is not going to last forever so I will do it when
it suits me rather than when it finally stops at an inconvenient moment.

Fitted a Grunfos Alpha+ 15-50. Quietest pump I have ever heard (if I put
my ear to it). Also took the opportunity to siphon some of the silt out
of the Myson Aerjec. Googling suggests they are prone to getting blocked.