Power Flushing - Yes or No

[Heat Kent]

Help & advice for a newbie RE power flushing...

From what I can gather there is an "associated document" to Part L of the Building Regulations, called the Domestic Heating Compliance Guide, which states that "central heating systems should be thoroughly cleaned and flushed out before installing a new boiler" (It’s a pretty boringread). With this being a guide and considering the use of the word “should” I assume there is no “legal” requirement. However, boiler manufacturers require you to follow this guide in order to validate their warrantee? This is a flush and clean, but not necessarily a power flush right?

However, if you type into Google “minimum requirement power flush” you’ll see that there are load of Power Flush companies who have the standard line “Power Flushing is the new minimum standard” implying that it is something you must have done.

I have been installing boilers (with someone who has his gas) and we simply drain the system, put a TF1 on the return, put a lime scale reducer on the cold feed and add an inhibiter when we refill. I’m new to plumbing and am finding all of your advice and help very useful and want to make sure I do everything correctly going forward. So please jump in and give your views, experiences and opinions. I’m leaning towards buying a Kamco CF90.

Thanks in advance.

 

[Heat Kent]

It would also concern me using power flushing on microboresystems and plastic pipework with pushfit fittings. If the valves/fittings areold and corroded will they start to leak if interrupted?

 

[Mike Jackson]

Just draining, fitting a TF1 and adding inhibitor is insufficient. The bare minimum required is a chemical cleanse.

 

[Heat Kent]

Just draining, fitting a TF1 and adding inhibitor is insufficient. The bare minimum required is a chemical cleanse.

That seems to be the general consensus, but do you do thisseveral days prior to flushing and let the system run or in and out in one/twodays? Also do you power flush or just rinse through? Can you power flush plasticpipes?

Thanks

 

[stratplus]

A lot of council boiler changes are done in a day. Y plan out, combi in. A case of drain system, do swop then add inhibiter and fill. No time to power flush and not expected to. (So I've heard).

 

[JAH HEATING]

A lot of council boiler changes are done in a day. Y plan out, combi in. A case of drain system, do swop then add inhibiter and fill. No time to power flush and not expected to. (So I've heard).

Most leave x400 in the system an then have a different engineer come round, drain it an refill with x100

 

[stratplus]

Not on the councils I've worked for. There'd be x400 in the system for months with the access rate being so poor.

 

[jase158]

the fact is that he is right, there is no legal requiremen in the building regs, but it is a manufacturer requirement, which then becomes a legal requirement as manufacturers instruction have more power then british standards so should be done.

But there is no clear fact on what sort of cleanse it is. could we just put x800 in the f and e? could we do a full powerflush?
what precedents a cleanse is debatable but we all know that not many people do it due to time and cost, but we should all be doing it.

 

[tamz]

It is not a manu requirement either as they point you to BS7593

Here is what it says there if you don't have it

5.2 Cleansing and flushing methodologies
There are three cleansing and flushing options, one of which should be applied.
1) Mechanically-assisted powered cleanse and flush (powerflushing) (see 5.3).
2) Mains pressure cleanse and flush for sealed systems and open-vented systems with the feed and vent temporarily capped-off (see 5.4).
3) Cleanse and flush using gravity, with the assistance of a circulator pump (see 5.5).

Powerflushing is most effective as this produces a more thorough clean, but the boiler manufacturer’s instructions should be checked to
establish whether powerflushing is acceptable. Powerflushing is the most effective method of cleansing existing systems, especially those
containing a high level of black magnetite sludge.
With all methodologies, reversing the flow will help to remove debris which might otherwise remain trapped.
An appropriate cleanser should be chosen. (Refer to manufacturers’ instructions.) The following factors should be taken into account:
a) the reason for cleaning;
b) the system materials, e.g. aluminium;
c) the age and condition of the system;
d) any specific problems identified;
e) any local restrictions on disposal of the effluent.
Hot flushing is more effective than cold flushing, but the cleanser
manufacturer’s instructions should be followed.

 

[Blake]

try sticking an extra £300 - 400 on your boiler quotes for a powerflush and see how many jobs you get

 

[jase158]

try sticking an extra £300 - 400 on your boiler quotes for a powerflush and see how many jobs you get

The thing is that most boiler installs round here are £2,000 plus for a straight swap, combi to combi, so why not do it in 2 days instead of 1? and fit the magnetic filter? I alwasy think its better to do a good job then to not!!

 

[jase158]

and for £2000, you are still making a nice profit aswell even if you are powerflushing!!

 

[Blake]

The thing is that most boiler installs round here are £2,000 plus for a straight swap, combi to combi, so why not do it in 2 days instead of 1? and fit the magnetic filter? I alwasy think its better to do a good job then to not!!

I totally agree with you, ultimately if you fit a boiler to a dirty system it will eventually come back to bite you in the backside after the manufacturer refuses to honour the warranty.

 

[Blake]

I don't actually know any installers that own a powerflush let alone carry one out prior to fitting a new boiler.

 

[jase158]

I totally agree with you, ultimately if you fit a boiler to a dirty system it will eventually come back to bite you in the backside after the manufacturer refuses to honour the warranty.

I have been back to a couple because my boss didnt flush them at the time. and one of the chaps i work with had to go back and put more screws in because manufacturers picked up on it!!

My old boss said, "do a job right first time evrytime"

 

[Heat Kent]

Hey guys, this is really helpful stuff, thanks a lot. I haveto say I would like to do everything by the book and take my time doing itproperly rather than in, out, grab the cash and run. I’ve spent most of todayreading up and considering the pros and cons and I have to say I much preferthe sound of the magnacleanse system to power flushing, it seems much lessharsh on the system, quicker, cleaner and smarter looking. What do you think?

 

[anz]

Not every system needs powerflushing, why do something that is not required?

I've changed boilers on systems in all kinds of conditions, the treatment they require varies.

Some systems will be ok with X800 in for a couple of hours and then a good hot and cold mains wash, others might just need a x400 and some will probably do fine with just a mains flush.

There are test kits available, where you take a sample of the system water and send it off to a laboratory and they send you a report confirming that it meets requirements.

Sentinel System Check Test Kit

 

[jase158]

Not every system needs powerflushing, why do something that is not required?

I've changed boilers on systems in all kinds of conditions, the treatment they require varies.

Some systems will be ok with X800 in for a couple of hours and then a good hot and cold mains wash, others might just need a x400 and some will probably do fine with just a mains flush.

There are test kits available, where you take a sample of the system water and send it off to a laboratory and they send you a report confirming that it meets requirements.

Sentinel System Check Test Kit

its very rare that they dont need flushing, most systems have some sludge in and if fitting a combi then the hot water heat exchanger will block up easily. so for me i would do it even if it didnt need it, better to be safe then sorry!!

 

[jase158]

I mean some sort of flushing, wether it is x800 in for a couple hours or a full flush, but its very rare that a system has been drained every year and inhibitor added every year and after any work done.

 

[AWheating]

its very simple..... the system needs flushing using whatever method is needed to make it clean and suitable for the new appliance. You base your flush on the system and its condition. Not flushing is not acceptable council installations included.

On council jobs many dont get flushed because the company doing the install wants to fit in a day and save money. This should not be confused with the thinking that the council knows or seeks to pay for work that is not done to the required standard. I bet if you read the contractual agreement between the council and any contractor it will state that the system shall be flushed or the system shall be fitted to current standards/methods and meet manufacturers instructions etc....

My old company (national energy supplier) pays as low as £130 to its engineers to change the boiler/system on some council/HA jobs, so i cant seen any install meeting the requirements tbh be that gas run, flushing or whatever. Who is to blame? the engineer cant afford to flush, the company may not have the margin to pay extra hours to flush, the council has gone for the cheapest quote expecting alot. Theres alot at fault with these types of contracts and a wide varity of standards of work.

the magnacleanse system flusher is a good bit of kit, but it does and cant replace a powerflush. Its better than just a chemical flush but its not closed to being a powerflush although the manufacturer may wish to tell you different to make it sell. Its best used alongside a powerflush machine.

 

[Heat Kent]

Myold company (national energy supplier) pays as low as £130 to its engineers tochange the boiler/system on some council/HA jobs, so i cant seen any installmeeting the requirements tbh be that gas run, flushing or whatever. Who is toblame? the engineer cant afford to flush, the company may not have the marginto pay extra hours to flush, the council has gone for the cheapest quoteexpecting alot. Theres alot at fault with these types of contracts and a widevarity of standards of work.

My experience of the industry thus far has been mostly site work - The two ofus will first fix a 3 bed HA and pump up in a day then it'll take another dayto do all rads, sanitary ware, boiler and cylinder and a third day to fit the kitchen sink, fill up, fire up and final. Obviously we don't get to do it in three consecutive days with other trades needing to get in and gear not turning up on time etc. But these are the kind of schedules we have to work, especially in the lead up to Christmas (then we have naff all to do in January). There is a commissioning guy who comes round before CML and I believe he’s supposed to add inhibiter and balance the system, check efficiency etc. I’m pretty sure hedoesn’t do any kind of flush though, so there will be general muck and crap floating around in the system (we pressure test with dirty water from barrels outside, there will be jet blue, flux, grit and all sorts in there).

It’s like you say, the builders want it done cheap and the firm have knocked 12% off the old price we get. I think a boiler is £75, a cylinder is £130, rads are £11 each and sanitary ware is £30 per item so about £400 for a full second fix, less your 12%

I need to get myself off site work and on to privates. It’s just good to have something to fall back on, but I don’t want to get stuck with a load of bad habits.

 

[AmritPedersen]

I always try to fit a magnaclean & do a clean with x800 on old systems or x400 on new. But using old boiler before I rip it out.

 

[AWheating]

My experience of the industry thus far has been mostly site work - The two ofus will first fix a 3 bed HA and pump up in a day then it'll take another dayto do all rads, sanitary ware, boiler and cylinder and a third day to fit the kitchen sink, fill up, fire up and final. Obviously we don't get to do it in three consecutive days with other trades needing to get in and gear not turning up on time etc. But these are the kind of schedules we have to work, especially in the lead up to Christmas (then we have naff all to do in January). There is a commissioning guy who comes round before CML and I believe he’s supposed to add inhibiter and balance the system, check efficiency etc. I’m pretty sure hedoesn’t do any kind of flush though, so there will be general muck and crap floating around in the system (we pressure test with dirty water from barrels outside, there will be jet blue, flux, grit and all sorts in there).

It’s like you say, the builders want it done cheap and the firm have knocked 12% off the old price we get. I think a boiler is £75, a cylinder is £130, rads are £11 each and sanitary ware is £30 per item so about £400 for a full second fix, less your 12%

I need to get myself off site work and on to privates. It’s just good to have something to fall back on, but I don’t want to get stuck with a load of bad habits.

honestly new build work is not great currently, but alot of contract work is in the same boat tbh.
i used to first fix new build, done easily over 500 new builds and i used to earn atleast £1000 min a week without breaking a sweat and that was with doing all the work to the book. like clipping every 400mm or so, sticking to all drill zones and structual regs, every pipe lagged and trace taped etc.... this would normally be 2 houses first fixed a week. On current prices id probably have to have increased to 4 houses a week and clip every mile

my old firm went from 12 to 15% profit margin on new build jobs to 1 to 3% so you can see how tight it is.

 

[Heat Kent]

Just got word our firm’s going down the pan…. Not in this week and possibly not in ever again. Still, ever the optimist, it seems I was learning some not so good habits, so I’ll take it as an opportunity to make a fresh start. I’m going to buy me a Magnacleanse tomorrow and do my house and a rental property I have, that’ll keep me occupied for a couple of days and we’ll call it a training week. I know a few guys who don’t do flushing, so I’ll see if I can do them a mutually beneficial deal if they pass me some work ;o)

 

[fontman]

I am on the fence regarding powerflushing, we recently did a job where the customer had been quoted by British Gas for a powerflush, taking an old floorstanding Potterton out (With Gravity hot water) but the ground floor rads were fed from under the floor. He found out from his neighbour that BG had done a similar job for him and caused leaks under the floor. So we went down the route of fitting a Conventional boiler, open vented central heating and an unvented Cylinder. All Rads came off and were flushed outside with a hosepipe with new valves both ends. Magnaclean fitted on the return, cleaner added ran for a day then flushed and re-filled and added inhibitor. No leaks! Happy Customer!
Powerflushing has its place but for this particular job it would have been too risky.