Is there a requirement to upgrade the controllability of the
individual radiators at the same time the boiler is replaced?
In practice I mean fitting TRVs but I would rather defer fitting them
until a later time.

Is there any other work that is likley to be insisted upon?


--

Graham.

%Profound_observation%

On 20/07/15 17:28, Graham. wrote:


Is there a requirement to upgrade the controllability of the
individual radiators at the same time the boiler is replaced?
In practice I mean fitting TRVs but I would rather defer fitting them
until a later time.

Is there any other work that is likley to be insisted upon?



Unless you are doing this directly through building control, I would not
have thought so.

GasSafe fitters self certify for Part L and gas purposes so whatever the
fitter is happy doing.

On 20/07/2015 17:28, Graham. wrote:


Is there a requirement to upgrade the controllability of the
individual radiators at the same time the boiler is replaced?
In practice I mean fitting TRVs but I would rather defer fitting them
until a later time.

Is there any other work that is likley to be insisted upon?



ICBW but my belief is that the only requirement is to have boiler
interlock, so that the boiler shuts down when all demands are satisfied.
This usually needs zone valve(s) and separate thermostats for space
heating[1] and HW. What have you currently got?

[1] One whole house room stat should suffice
--
Cheers,
Roger
____________
Please reply to Newsgroup. Whilst email address is valid, it is seldom
checked.

On Mon, 20 Jul 2015 17:43:04 +0100, Roger Mills
wrote:

On 20/07/2015 17:28, Graham. wrote:


Is there a requirement to upgrade the controllability of the
individual radiators at the same time the boiler is replaced?
In practice I mean fitting TRVs but I would rather defer fitting them
until a later time.

Is there any other work that is likley to be insisted upon?



ICBW but my belief is that the only requirement is to have boiler
interlock, so that the boiler shuts down when all demands are satisfied.
This usually needs zone valve(s) and separate thermostats for space
heating[1] and HW. What have you currently got?

[1] One whole house room stat should suffice


Currently a lump of cast-iron in a lean-to feeding S-Plan pipe work.
Independent control of DHW and CH.

I want to replace it with a wall-mounted combi in the kitchen.
Shouldn't be too difficult for the engineer, as cold feed, feed to hot
taps, 22mm gas with prob four 90deg bends when complete, and rad flow
& return are all at floor or under-floor level at the proposed site.

Is that gas supply likley to be OK for a combi? Four bed semi, one
bathroom and a frugal owner (me) who won't mind it being a little
under-powered?



--

Graham.

%Profound_observation%

"Roger Mills" wrote in message
...
On 20/07/2015 17:28, Graham. wrote:


Is there a requirement to upgrade the controllability of the
individual radiators at the same time the boiler is replaced?
In practice I mean fitting TRVs but I would rather defer fitting them
until a later time.

Is there any other work that is likley to be insisted upon?



ICBW but my belief is that the only requirement is to have boiler
interlock, so that the boiler shuts down when all demands are satisfied.
This usually needs zone valve(s) and separate thermostats for space
heating[1] and HW. What have you currently got?

[1] One whole house room stat should suffice

Best practice would say that the TRVs are required. But is a new boiler a
new system?



--
Adam

Graham. wrote:
On Mon, 20 Jul 2015 17:43:04 +0100, Roger
wrote:

On 20/07/2015 17:28, Graham. wrote:


Is there a requirement to upgrade the controllability of the
individual radiators at the same time the boiler is replaced?
In practice I mean fitting TRVs but I would rather defer fitting them
until a later time.

Is there any other work that is likley to be insisted upon?



ICBW but my belief is that the only requirement is to have boiler
interlock, so that the boiler shuts down when all demands are satisfied.
This usually needs zone valve(s) and separate thermostats for space
heating[1] and HW. What have you currently got?

[1] One whole house room stat should suffice


Currently a lump of cast-iron in a lean-to feeding S-Plan pipe work.
Independent control of DHW and CH.

I want to replace it with a wall-mounted combi in the kitchen.
Shouldn't be too difficult for the engineer, as cold feed, feed to hot
taps, 22mm gas with prob four 90deg bends when complete, and rad flow
& return are all at floor or under-floor level at the proposed site.

Is that gas supply likley to be OK for a combi? Four bed semi, one
bathroom and a frugal owner (me) who won't mind it being a little
under-powered?




May be a problem when you come to sell it. I would allow for the cost
of putting in a new boiler and tanks when making an offer on the house,

On 20/07/2015 20:12, Capitol wrote:
Graham. wrote:
On Mon, 20 Jul 2015 17:43:04 +0100, Roger
wrote:

On 20/07/2015 17:28, Graham. wrote:


Is there a requirement to upgrade the controllability of the
individual radiators at the same time the boiler is replaced?
In practice I mean fitting TRVs but I would rather defer fitting them
until a later time.

Is there any other work that is likley to be insisted upon?



ICBW but my belief is that the only requirement is to have boiler
interlock, so that the boiler shuts down when all demands are satisfied.
This usually needs zone valve(s) and separate thermostats for space
heating[1] and HW. What have you currently got?

[1] One whole house room stat should suffice


Currently a lump of cast-iron in a lean-to feeding S-Plan pipe work.
Independent control of DHW and CH.

I want to replace it with a wall-mounted combi in the kitchen.
Shouldn't be too difficult for the engineer, as cold feed, feed to hot
taps, 22mm gas with prob four 90deg bends when complete, and rad flow
& return are all at floor or under-floor level at the proposed site.

Is that gas supply likley to be OK for a combi? Four bed semi, one
bathroom and a frugal owner (me) who won't mind it being a little
under-powered?

May be a problem when you come to sell it. I would allow for the
cost of putting in a new boiler and tanks when making an offer on the
house,

That would, of course, be your prerogative. I'm sure someone else would
take a more practical viewpoint.

Of course, after 5 years it might well need replacing in any case!

In article ,
Graham. writes:

Is that gas supply likley to be OK for a combi?

It's unlikely, although not impossible. Combi is likely to be ~3 times
the power of your cast iron lump, and existing pipework may drop too
much pressure, in which case it will need replacing with a thicker
pipe, possibly with a more direct route and/or fewer elbows. (Often,
pipework is already undersized for existing boiler, since back when
this wasn't an issue.) If you can give the pipe length, diameter,
number of elbows, and number of formed bends, someone can work out the
max boiler power it will support. Get's more complicated if there are
any other gas appliances T-ed off it.

Four bed semi, one
bathroom and a frugal owner (me) who won't mind it being a little
under-powered?

You can't get away with low pressure on gas inlet - it will fail the
commissioning test, and it will fail any landlord safety check (and
the boiler might not work properly). You could use a lower powered
combi, which might get you inside the max power your existing pipework
supports if the current pipework is close.

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

In article ,
"ARW" writes:
"Roger Mills" wrote in message
...
On 20/07/2015 17:28, Graham. wrote:


Is there a requirement to upgrade the controllability of the
individual radiators at the same time the boiler is replaced?
In practice I mean fitting TRVs but I would rather defer fitting them
until a later time.

Is there any other work that is likley to be insisted upon?



ICBW but my belief is that the only requirement is to have boiler
interlock, so that the boiler shuts down when all demands are satisfied.
This usually needs zone valve(s) and separate thermostats for space
heating[1] and HW. What have you currently got?

[1] One whole house room stat should suffice

Best practice would say that the TRVs are required. But is a new boiler a
new system?

A new boiler requires bringing controls up to current regs.
The regs do not specify needing TRVs, but you do need something better
than a single roomstat controlling the whole house, unless the house
is very small. Zoning and/or TRVs are options, but the precise method
is not dictated. The other requirement is that the boiler must switch
off when no zones are calling for heat - it's not allowed to continue
heating a bypass loop, so you can't use only TRV's - you need some type
of interlock to shut boiler off if they all close.

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

On Mon, 20 Jul 2015 20:38:22 +0000 (UTC),
(Andrew Gabriel) wrote:

In article ,
Graham. writes:

Is that gas supply likley to be OK for a combi?

It's unlikely, although not impossible. Combi is likely to be ~3 times
the power of your cast iron lump, and existing pipework may drop too
much pressure, in which case it will need replacing with a thicker
pipe, possibly with a more direct route and/or fewer elbows. (Often,
pipework is already undersized for existing boiler, since back when
this wasn't an issue.) If you can give the pipe length, diameter,
number of elbows, and number of formed bends, someone can work out the
max boiler power it will support. Get's more complicated if there are
any other gas appliances T-ed off it.

Four bed semi, one
bathroom and a frugal owner (me) who won't mind it being a little
under-powered?

You can't get away with low pressure on gas inlet - it will fail the
commissioning test, and it will fail any landlord safety check (and
the boiler might not work properly). You could use a lower powered
combi, which might get you inside the max power your existing pipework
supports if the current pipework is close.


It's quite short, 11-12m

ISTR that each 90deg bend increases the effective length by half a
metre so let's say 15M. This appears to be the top limit for a 32 kW
boiler

--

Graham.

%Profound_observation%

On 7/20/2015 10:37 PM, Graham. wrote:
On Mon, 20 Jul 2015 20:38:22 +0000 (UTC),
(Andrew Gabriel) wrote:

In article ,
Graham. writes:

Is that gas supply likley to be OK for a combi?

It's unlikely, although not impossible. Combi is likely to be ~3 times
the power of your cast iron lump, and existing pipework may drop too
much pressure, in which case it will need replacing with a thicker
pipe, possibly with a more direct route and/or fewer elbows. (Often,
pipework is already undersized for existing boiler, since back when
this wasn't an issue.) If you can give the pipe length, diameter,
number of elbows, and number of formed bends, someone can work out the
max boiler power it will support. Get's more complicated if there are
any other gas appliances T-ed off it.

Four bed semi, one
bathroom and a frugal owner (me) who won't mind it being a little
under-powered?

You can't get away with low pressure on gas inlet - it will fail the
commissioning test, and it will fail any landlord safety check (and
the boiler might not work properly). You could use a lower powered
combi, which might get you inside the max power your existing pipework
supports if the current pipework is close.


It's quite short, 11-12m

ISTR that each 90deg bend increases the effective length by half a
metre so let's say 15M.

0.5m for an elbow or tee, 0.3m for a "Pulled" bend or swept 90.

This appears to be the top limit for a 32 kW
boiler

You have omitted a key detail, the pipe diameter.

15m effective length, gives a maximum flow rate of 1.1m^3/h for 15mm,
and 3.4m^3/h for 22mm.

(the former would be inadequate for any combi, while the latter good
enough for almost all of them)

Conversions available he

http://wiki.diyfaq.org.uk/index.php?title=Gas_units


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

On Tue, 21 Jul 2015 02:46:32 +0100, John Rumm
wrote:

On 7/20/2015 10:37 PM, Graham. wrote:
On Mon, 20 Jul 2015 20:38:22 +0000 (UTC),
(Andrew Gabriel) wrote:

In article ,
Graham. writes:

Is that gas supply likley to be OK for a combi?

It's unlikely, although not impossible. Combi is likely to be ~3 times
the power of your cast iron lump, and existing pipework may drop too
much pressure, in which case it will need replacing with a thicker
pipe, possibly with a more direct route and/or fewer elbows. (Often,
pipework is already undersized for existing boiler, since back when
this wasn't an issue.) If you can give the pipe length, diameter,
number of elbows, and number of formed bends, someone can work out the
max boiler power it will support. Get's more complicated if there are
any other gas appliances T-ed off it.

Four bed semi, one
bathroom and a frugal owner (me) who won't mind it being a little
under-powered?

You can't get away with low pressure on gas inlet - it will fail the
commissioning test, and it will fail any landlord safety check (and
the boiler might not work properly). You could use a lower powered
combi, which might get you inside the max power your existing pipework
supports if the current pipework is close.


It's quite short, 11-12m

ISTR that each 90deg bend increases the effective length by half a
metre so let's say 15M.

0.5m for an elbow or tee, 0.3m for a "Pulled" bend or swept 90.

This appears to be the top limit for a 32 kW
boiler

You have omitted a key detail, the pipe diameter.

15m effective length, gives a maximum flow rate of 1.1m^3/h for 15mm,
and 3.4m^3/h for 22mm.

(the former would be inadequate for any combi, while the latter good
enough for almost all of them)

Conversions available he

http://wiki.diyfaq.org.uk/index.php?title=Gas_units

Sorry John I was embellishing my previous post where I gave the
diameter (22mm) but omitted the length.



--

Graham.

%Profound_observation%

On 20/07/15 18:36, Graham. wrote:

Is that gas supply likley to be OK for a combi? Four bed semi, one
bathroom and a frugal owner (me) who won't mind it being a little
under-powered?

If the pipe to the boiler location is only 15mm it will probably need to
be upgraded to 22mm.

On 20/07/2015 18:36, Graham. wrote:
On Mon, 20 Jul 2015 17:43:04 +0100, Roger
wrote:

On 20/07/2015 17:28, Graham. wrote:


Is there a requirement to upgrade the controllability of the
individual radiators at the same time the boiler is replaced?
In practice I mean fitting TRVs but I would rather defer fitting them
until a later time.

Is there any other work that is likley to be insisted upon?



ICBW but my belief is that the only requirement is to have boiler
interlock, so that the boiler shuts down when all demands are satisfied.
This usually needs zone valve(s) and separate thermostats for space
heating[1] and HW. What have you currently got?

[1] One whole house room stat should suffice


Currently a lump of cast-iron in a lean-to feeding S-Plan pipe work.
Independent control of DHW and CH.

I want to replace it with a wall-mounted combi in the kitchen.
Shouldn't be too difficult for the engineer, as cold feed, feed to hot
taps, 22mm gas with prob four 90deg bends when complete, and rad flow
& return are all at floor or under-floor level at the proposed site.


Are you getting rid of your HW cylinder (not recommended!) and relying
on 'instant' hot water for all your HW requirements - bath, shower,
washbasin, kitchen sink, etc.? If so, you won't need your S-Plan zone
valves any more - and you can control the CH side of the combi with
whatever stat currently switches the CH zone valve. [Unless, course, you
wanted to re-deploy the HW zone valve in order to create two separate CH
zones].

The alternative - preferable in my opinion - is to keep the HW cylinder
and S-Plan system and drive all of that from the CH side of the combi -
and just use the combi's instant hot water for the kitchen sink.

Others, such as Drivel - wonder where he went? - may not agree.
--
Cheers,
Roger
____________
Please reply to Newsgroup. Whilst email address is valid, it is seldom
checked.

In message , Roger Mills
writes
On 20/07/2015 18:36, Graham. wrote:
On Mon, 20 Jul 2015 17:43:04 +0100, Roger
wrote:

On 20/07/2015 17:28, Graham. wrote:


Is there a requirement to upgrade the controllability of the
individual radiators at the same time the boiler is replaced?
In practice I mean fitting TRVs but I would rather defer fitting them
until a later time.

Is there any other work that is likley to be insisted upon?



ICBW but my belief is that the only requirement is to have boiler
interlock, so that the boiler shuts down when all demands are satisfied.
This usually needs zone valve(s) and separate thermostats for space
heating[1] and HW. What have you currently got?

[1] One whole house room stat should suffice


Currently a lump of cast-iron in a lean-to feeding S-Plan pipe work.
Independent control of DHW and CH.

I want to replace it with a wall-mounted combi in the kitchen.
Shouldn't be too difficult for the engineer, as cold feed, feed to hot
taps, 22mm gas with prob four 90deg bends when complete, and rad flow
& return are all at floor or under-floor level at the proposed site.


Are you getting rid of your HW cylinder (not recommended!) and relying
on 'instant' hot water for all your HW requirements - bath, shower,
washbasin, kitchen sink, etc.? If so, you won't need your S-Plan zone
valves any more - and you can control the CH side of the combi with
whatever stat currently switches the CH zone valve. [Unless, course,
you wanted to re-deploy the HW zone valve in order to create two
separate CH zones].

The alternative - preferable in my opinion - is to keep the HW cylinder
and S-Plan system and drive all of that from the CH side of the combi -
and just use the combi's instant hot water for the kitchen sink.

Others, such as Drivel - wonder where he went? - may not agree.

It rather depends.

In the old house I took out the tank and put in a combi, and for that
house it was a good option.

I wouldn't do it here though
--
Chris French

On 7/21/2015 4:32 AM, Graham. wrote:
On Tue, 21 Jul 2015 02:46:32 +0100, John Rumm
wrote:

On 7/20/2015 10:37 PM, Graham. wrote:
On Mon, 20 Jul 2015 20:38:22 +0000 (UTC),
(Andrew Gabriel) wrote:

In article ,
Graham. writes:

Is that gas supply likley to be OK for a combi?

It's unlikely, although not impossible. Combi is likely to be ~3 times
the power of your cast iron lump, and existing pipework may drop too
much pressure, in which case it will need replacing with a thicker
pipe, possibly with a more direct route and/or fewer elbows. (Often,
pipework is already undersized for existing boiler, since back when
this wasn't an issue.) If you can give the pipe length, diameter,
number of elbows, and number of formed bends, someone can work out the
max boiler power it will support. Get's more complicated if there are
any other gas appliances T-ed off it.

Four bed semi, one
bathroom and a frugal owner (me) who won't mind it being a little
under-powered?

You can't get away with low pressure on gas inlet - it will fail the
commissioning test, and it will fail any landlord safety check (and
the boiler might not work properly). You could use a lower powered
combi, which might get you inside the max power your existing pipework
supports if the current pipework is close.


It's quite short, 11-12m

ISTR that each 90deg bend increases the effective length by half a
metre so let's say 15M.

0.5m for an elbow or tee, 0.3m for a "Pulled" bend or swept 90.

This appears to be the top limit for a 32 kW
boiler

You have omitted a key detail, the pipe diameter.

15m effective length, gives a maximum flow rate of 1.1m^3/h for 15mm,
and 3.4m^3/h for 22mm.

(the former would be inadequate for any combi, while the latter good
enough for almost all of them)

Conversions available he

http://wiki.diyfaq.org.uk/index.php?title=Gas_units

Sorry John I was embellishing my previous post where I gave the
diameter (22mm) but omitted the length.

My apologies - I missed that.


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/