New Boiler Install - Is Power Flush Necessary?

pennypincher3562

Hi

I am planning on getting a new Glow Worm boiler installed, to replace my old leaky boiler which is about 12 years old.

I've been told that after installation of the Glow Worm, a Power Flush should be conducted and a magnet filter fitted. The reason given was that a 'dirty system' could invalidate the warranty on my new boiler. Is this correct?

I see on one quote, they mention a 'chemical flush.' Is this the same as a 'power flush'?

Thanks in advance.

System

A blocked boiler will invalidate the warranty.

Chemical or power flush depends on what investigations your installer has carried out. If radiators are not getting hot, then the default position is a full power flush. Advice here: (it may not be fully up to date as some boiler manufacturers are now happy for systems to use softened water)

http://www.centralheating.co.uk/useful-information/water-treatment-for-central-heating-systems

It's worth noting that Germany has just changed its guidance. Power flushes and water treatment are no longer required. Boilers are now filled with PH neutral water with a magnetic filter and air extractor (such as Spirotech RV2/MV2). No doubt the UK will follow in about 10 years time!!

I am going through the same machinations at the moment: one installer advises a power flush and two are happy with chemicals only.

Cardew

Some prices quoted for a Powerflush are unbelievable - especially British Gas.

pennypincher3562

Hengus wrote: »

A blocked boiler will invalidate the warranty.

Chemical or power flush depends on what investigations your installer has carried out. If radiators are not getting hot, then the default position is a full power flush. Advice here: (it may not be fully up to date as some boiler manufacturers are now happy for systems to use softened water)

http://www.centralheating.co.uk/useful-information/water-treatment-for-central-heating-systems

Thanks Hengus. No investigation has been carried out. 2 engineers came out, and one said they would do a power flush before boiler installation, the other said a chemical flush.

@Cardew - I am not planning to use the company you mention. :-)

reeac

I have to say that I do wonder about this Powerflush thing. We had an entirely new c.h. System installed in a house in early 1976 and lived there for 22 years with no flushing of any kind and no leaky or cold radiators. Our present system was installed when our place was built in 1997 so we've had it for 19 years, again with no flushing. Have we just been lucky?

bigfreddiel

A power flush can cause considerable damage, joints can be fractured and if the pipes are under floorboards etc it will be murder trying to fix it.

Good luck fj

macman

Copied from a random Glow Worm install manual:

Prior to starting work, the system must be thoroughly flushed
using a propriety cleanser such as Sentinel X300 to eliminate
any foreign matter and contamination e.g. metal filings, solder
particles, oil, grease etc.

No mention of powerflushing.

Farway

No real comments as to "needed" or not, but when I had new combi fitted, about 3 years ago, a powerflush was part of the install, not sure if any chemicals were involved in this, but the gunge & muck that came out of my 40 year old pipes & rads was horrendous, glad I had it done

No leaks etc either, was I lucky? Never know

Just to say that sometimes a flush is good IMO,

Pincher

If the plumber is willing he can put in a return flow filter, which will catch any dirt coming towards the old boiler.

https://www.sentinelprotects.com/uk/products/domestic/central-heating-systems/sentinel-system-filter

He then puts in a slow acting cleaner, like

https://www.sentinelprotects.com/uk/products/domestic/central-heating-systems/sentinel-x400-system-restorer

Leave it running for weeks, and clear the filter frequently.

Note that X800 "Rapid cleaner for systems older than six months and powerflushing" is not meant for long term use. You are supposed to put it in, clean, and then flush it out, and refill with fresh water, plus inhibitor.

This assumes your old boiler pump still works.

Fernox has a similar set of products, instead of Sentinel.

Note that radiators that are half cold/half hot can be removed and flushed in a garden with a hose. If it's stubborn, it's easier to just buy another one.

System

Pincher wrote: »

If the plumber is willing he can put in a return flow filter, which will catch any dirt coming towards the old boiler.

https://www.sentinelprotects.com/uk/products/domestic/central-heating-systems/sentinel-system-filter

He then puts in a slow acting cleaner, like

https://www.sentinelprotects.com/uk/products/domestic/central-heating-systems/sentinel-x400-system-restorer

Leave it running for weeks, and clear the filter frequently.

Note that X800 "Rapid cleaner for systems older than six months and powerflushing" is not meant for long term use. You are supposed to put it in, clean, and then flush it out, and refill with fresh water, plus inhibitor.

This assumes your old boiler pump still works.

Fernox has a similar set of products, instead of Sentinel.

Note that radiators that are half cold/half hot can be removed and flushed in a garden with a hose. If it's stubborn, it's easier to just buy another one.

As I said above, German standards have just changed as follows (VDI2035): (Forgive the Google translate)

No chemicals

Anti-corrosion procedures in conjunction with different materials are very clearly described for the practitioner. The VDI continuously and clearly indicates that the "chemical bomb" in the form of additives must or should only be used in the most seldom of cases. The VDI advocates precisely the opposite thus clearing up the jungle of water chemistry in heating systems.

ph-value

Importantly high value is placed on the awareness and monitoring of the ph-value. Depending on the materials used, it should lie between 8.2 and 10. The expert will have to get used to the necessity of being aware about the necessary or existing ph-value of the heating water. In addition to the oxygen content, it is an important factor for the possibility of the presence of corrosion processes.

The ph-value is simple to check without a large amount of technical expenditure. Systems require a certain amount of time for the development of or stabilization of the ph-value of the heating water. Usually, no external assistance is necessary in order to adjust the required alkaline range. The so-called inherent alkaline treatment takes place on its own after the system is filled and should be checked after 8 to 12 weeks of operating time.

C_Mababejive

My advice-If it says it in the boiler installation manual, then have it done. If i were an installer, i would not do a boiler change if the customer said they didnt want it. Now whether that cleansing mechanism is what is described as a "powerflush" or a "cleansing" using for example sentinel x300 or similar, does not matter. What DOES matter is that the system is cleansed so as to meet the new boiler manufs requirements ,before the new boiler is installed.

I would NOT fit a new high efficiency boiler to an existing system without cleansing it ,and without fitting a filter as part of the installation.