Is a power flush required if fitting a new boiler?

[sunflowers8]

Hi

I've just had a plumber price up the fitting of a Worcester 24i junior combi boiler. When I asked if this included a power flush, he said this was not required because (1) the filter would eliminate the need for this (2) as he is replacing a combi for a combi there was no need (3) the small size of the pipework (not sure if it's too small or less sludge can get through or what).

Is this guy talking rubbish or is he right? Seemed like a very genuine guy and not pushy in any way at all.

As an aside, is a seperate thermostat control really necessary? Our house is small and it takes two seconds to walk to the boiler to change the temp. Read somewhere it is more efficient to have the thermostat but not sure why?

Many thanks in advance and apologies if the questions sound a bit dumb!

 

[lame plumber]

it all depends on a lot of things. best you get some other quotes in before you make your mind up. room stats are also required under building regs and will save you money in the long term.

 

[village idiot]

Even you have confirmed that it is a small house. So I would have done the same. If your current boiler is still working, I will come a day in advance of the refit and dose with treatment, then on replacement flush again with cold, then hot etc and dose with inhibitant. Fit a filter, pay you a visit in two weeks, check and clean filter. Sorted.

I personally will not bother to power flush your system. Just my view

 

[A1P]

Manufacturers usually specify a clean system for guarantee purposes.As you will see from similar threads this is not specifically a power flush.On old systems which have not been maintained properly a power flush may be the best option.It is possible to test your system to determine this.It sounds as if you may have micro bore pipework which is harder to power flush.As for the filter eliminating the need for it,a filter is designed to keep your system clean not clean it up.I don't know why a combi to combi is relevant.The thermostat offers control and should ensure the system operates efficiently to your requirements.If you are going to follow up your questions you might look at boiler choice.Nothing wrong with the Worcs. but there are good alternatives with long guarantees up to 7 years.Baxi Duotec and Ideal logic plus.Have you had alternative quotes? With careful selection you should also be able to avoid the dreaded VAT.

 

[Ray Stafford]

Hi Sunflowers8, and welcome to the forum.

Taking your last question first, yes, there is a requirement for "boiler interlock" in the building regs. By far the easiest way of achieving this is to use a roomstat. It isn't so you can change the temperature (although it does obviously have that advantage). It is so there is something positively telling the boiler "shut down now, the house is warm enough" when a temperature is achieved.

It isn't expensive to do, and you will probably get your money back in your first years fuel bill.

Whether the existing system needs power flushing depends on the condition it is in. The fact that it is currently a combi is only relevant in the sense that modernm sealed systems are less likely to be filled with crud than older, open vented systems. He is right that the filter will also help. It isn't possible to tell over the internet whether your system needs power flushing - in fact, it isn't always easy to tell if a system needed flushing, until you flush it!

The "belt and braces" answer is to powerflush everything. In actual fact, a hot chemical flush, plus a cold mains flush will often do the job just fine.

 

[LPC]

I powerflush every system before installing a new boiler (and install a Magnetic filter afterwards). If it's a small house and an existing sealed system, the powerflush will not take very long.

I do it because then I know the boiler has the best chance going forward. Get some other quotes, if you get one with a powerflush for no more money then you're well in.

And yes, you should have a thermostat installed. They are required and once you have one you'll wonder what life was like without it.

 

[village idiot]

Hi Sunflowers8, and welcome to the forum.
In actual fact, a hot chemical flush, plus a cold mains flush will often do the job just fine.

Now that is a properly scripted response. Now I see why I heard in the grapevine that Ray S is planning on scripting and directing a movie.

As far as I am concerned, in most cases, if you are prepared to take the time to dose with chemical and hot flush then cold flush, you will be able to tell if all is well, then proceed. The idea of powerflushing everything infront of you beats me.

 

[AWheating]

the question is whats required? well the boiler manufacturer will require you to flush the system to meet the british standards. This can be done in one of 3 methods depending on the condition of your existing system, which is the important part. The condition of your existing system is the deciding factor. heavily sludged up and it will need a proper power flush which will take atleast 4-6 hours min. A system in good condition may just require a chemical flush using gravity or mains pressure.

If you have microbore pipework then is probably best to remove rads and flush them out and chem flush as normal practice.

remember its whats required not what your engineer wants to do. Some times you may not be 100% sure whats needed before you start working on the system.

 

[TBServices]

Depends on the system. Most of the time, no. Waste of time

I always fit a filter, external filling loop and drain off on the opposite pipe to mains flush with the boiler isolated once the chemical has been running round long enough.

 

[Whyme]

When we fit boilers we fit a magnetic filter and use an agitator to remove most black sludge form the rads, also a lot of manufacturers extend the guarantee with one fitted. a 24i seems a bit small though. any idea what kw your old boiler is cos you might want to match it (for hot water).

 

[sunflowers8]

Hi all

Thanks very much for taking the time to reply. Much appreciated.

My existing boiler is a Britony Combi 80. The heat output is 24kw.

So much to consider. I have somebody else coming tomorrow so will see what he says, but I feel a bit duped. You'd think a good heating engineer would know the thermostat is a building regs requirement. He recommended the 24i over the 28i, which was my preferred choice. I'd have thought that for a small 3 bedroom house a 28i would be more suitable.

Thanks again for your comments.

 

[TBServices]

For a 3 bed house you'll probably only need 12-15kw of heating. Combi's are sized for hot water demand.

Forget the first guy ever came to your house. 1. He wants to fit a worcester junior (rubbish rubbish rubbish boilers) 2. He sounds like a muppet.

Get someone round who knows what they're doing. Post your location and I'm sure there'll be someone local to provide a quote.

 

[GasmanxxxR1]

In answer to your question, No it doesn't 'need' a powerflush and Yes it does 'need' a room stat

Next!

 

[Whyme]

You'll find a lot of suspect installers fit smaller boilers because there cheaper ( on a fit and forget basis). As said he should have told you about room stats. good luck with the next chap.

 

[Ray Stafford]

I am just getting a funny vibe from this thread.

I wonder if the OP has put the installer under a lot of price pressure?

"Everything has to be perfect, but I don't have much money"

I can just visualise a guy under price pressure here, thinking "well, it could still be an earner, if we change the 28kw to 24kw, scrap the roomstat, cross our fingers on the powerflush..."

 

[Whyme]

@sunflowers8 have a few quotes and a few chats with them all. youve quite a bit of info from here so hopefully you wont go for a small combi or the cheapest. bide your time and look around untill your comfortable with spending what is in this day and age a lot of money..

 

[TBServices]

FYI. You can save a lot by opting for a boiler other than WB, and you'll get a lot more for your money. The junior is a terrible boiler - if it didn't have the WB badge on it, it would be £400 and all the worcester lovers would laugh at how pants it is, and moan about how awful they are to fix.

 

[sunflowers8]

FYI. You can save a lot by opting for a boiler other than WB, and you'll get a lot more for your money. The junior is a terrible boiler - if it didn't have the WB badge on it, it would be £400 and all the worcester lovers would laugh at how pants it is, and moan about how awful they are to fix.

Thanks again all.

I don't want to pay over the odds but am willing to fork out what's necessary, not just the cheapest model to get by.

I have to to say I am now slightly put off by the Junior. I chose this after researching on Which, which rated it 84%. But I guess you guys are the experts. Can anybody offer any other alternatives please? I've noted the comments about Baxi duotech or Ideal logic plus.

Again, many thanks in advance.

 

[Nostrum]

He may have specced a 24 to save a gas re-run.

 

[TBServices]

He may have specced a 24 to save a gas re-run.

Doubtful.

 

[TBServices]

The OP sound pretty clued up.

The fact he has said no room stat is ridiculous.

No point speccing a heating and hot water install that costs thousands, around an electric shower - they might want to rip it out in a year!

 

[glenno1]

Im not convinced powerflushing works as chemicals react with right temperature and the temperature drops too much as it travels round the system

 

[sunflowers8]

Just wanted to provide a quick update. Have had a second quote of approx £2k for the Worcester Greenstar 30si with thermostat, powerflush and filter (I think). He clearly loves Worcester and said the only other brand he would recommend was Valliant but as this doesn't come with a seven year warranty he thinks it's not as good a deal.

 

[PowerFlusher2]

Have a look at Intergas, had one put in last year, excellent bit of kit, and only 4 moving parts!

 

[AWheating]

Im not convinced powerflushing works as chemicals react with right temperature and the temperature drops too much as it travels round the system

Convinced because of what? Chemical cleaners work hot or cold, heat accelerates the process yes but does not activate the process. Most chemical cleaning processes are accelerated by heat, just like doing the washing up, but washing liquid still works in cold water. A power flushing machines biggest advantage is the flow rate of the water it circulates. Many machines are now rated at 100 lpm or higher and it's the flow of water that does the job better than compared to a mains flush only. Either way if you can heat the system for a mains flush you can for a powerflush.

unless you only flush with the new boiler in which case is like delivering a new born baby in a cemetry.