Hi,

We have recently moved to a larger house with what has turned out to be
an unusual heating system. We have just had all the rads replaced with
Stellrads and a new Grundfoss SS pump fitted. It turns out that
downstairs is a single pipe system in the solid floor but upstairs is
modern two. The upstairs rads are fine but downstairs still are not
very efficient. I have tried balancing the system by stopping down all
the upstairs rads so that they are only open half a turn and this has
helped downstairs. I dont really want to get involved with putting a
dual pipe system in downstairs however I do have an idea to improve
things further, what if I insert a stop down valve in the main pipe
feed to the upstairs system therefore forcing more water downstairs?
Practical? Difficult?
BTW Is it common practice to run a Grundfoss SS on the highest speed
setting 3?

Thanks for any advice,
Matthew

Thanks for any advice,

Good luck. It helps if the upstairs rads have working and well adjusted
TRVs. When these close down, more water is forced through the single pipe
system.

However, you may never be able to get the system working particularly
satisfactorily with the current pipework layout. The overall upstairs
balance may help. If the pipework is already in a suitable configuration for
such a valve, you may find subzoning upstairs and downstairs helps,
particularly if it is possible to have a pump for each zone.

Christian.

In article .com,
"Matthew" writes:
Hi,

We have recently moved to a larger house with what has turned out to be
an unusual heating system. We have just had all the rads replaced with
Stellrads and a new Grundfoss SS pump fitted. It turns out that
downstairs is a single pipe system in the solid floor but upstairs is
modern two. The upstairs rads are fine but downstairs still are not
very efficient. I have tried balancing the system by stopping down all
the upstairs rads so that they are only open half a turn and this has
helped downstairs. I dont really want to get involved with putting a
dual pipe system in downstairs

That's not necessary. Single pipe systems worked fine. It's
just that there aren't so many plumbers around nowadays who
understood exactly how they worked, and the thermal calculations
are more complex and well beyond most plumbers today.

however I do have an idea to improve
things further, what if I insert a stop down valve in the main pipe
feed to the upstairs system therefore forcing more water downstairs?
Practical? Difficult?

Are you sure there isn't one already? In the days of single
pipe systems, the balancing was normally done per circuit
rather than per radiator anyway, and a mixture of single pipe
and dual pipe circuits was not uncommon in the same system.

--
Andrew Gabriel

Matthew wrote:
Hi,

We have recently moved to a larger house with what has turned out to
be
an unusual heating system. We have just had all the rads replaced
with
Stellrads and a new Grundfoss SS pump fitted. It turns out that
downstairs is a single pipe system in the solid floor but upstairs is
modern two. The upstairs rads are fine but downstairs still are not
very efficient. I have tried balancing the system by stopping down
all
the upstairs rads so that they are only open half a turn and this has
helped downstairs. I dont really want to get involved with putting a
dual pipe system in downstairs however I do have an idea to improve
things further, what if I insert a stop down valve in the main pipe
feed to the upstairs system therefore forcing more water downstairs?
Practical? Difficult?
BTW Is it common practice to run a Grundfoss SS on the highest speed
setting 3?

Thanks for any advice,
Matthew

If you can pump signficantly faster than usual thru the single pipe
section, it should work fine.

If your existing pump cant get the last rad on the single line hot,
maybe a 2nd pump in the single pipe circuit only.

It isnt ideal, but it can work well enough.


NT