Cost of full power flush?

[jellyxat]

We've had a quote from a highly recommended plumber for a full power flush, at £1100 plus vat. It's a 5-bed Edwardian semi. Is that price reasonable?

We don't really want to have lots of plumber come in to do quotes, especially as this plumber seemed very knowledgeable and is highly recommended.

I want to sense check here, as online seems to suggest £500 is standard. We're in London.

Thank you!

Maybe @pigletjohn will know the answer? Hopeful tag

Why? Generally it's a bit of a scam.

£1100 sounds a bit high, and £500 sounds a bit low.

It will depend on area.

It will probably be half a day's work, possibly more, for one person with an assistant to go round turning things on and off.

This is a time of year when heating engineers are working their socks off to help people whose heating has broken down. Perhaps your plumber is considering what she would make if she spent her time fitting a new boiler instead.

You might get better prices in June or July, once they're home from their yachts.

Why do you need it done?

The reality is when fitting boilers they are making £1200-1500 in a day so doing boiler services or power flushes isn't as lucrative.

But as per @PigletInABlanketJohn, why does it need doing? Whenever we decorate a room we drop the radiators and flush them out. We have a system filter with inhibitor and have fairly little debris in our radiators

Many years ago, we were having issues with our heating. It was an old system when we lived in. One if many things we tried to have done to help it was a power flush. It did help in some rooms and settle most of the noise issues we had too. We have a 5 bed 1930s house in a hard water area. Ultimately though we eventually replaced pipes, radiators and new boiler plus water softener.

We recently had all our radiators replaced, and intend to get a new boiler in the new year. Should we get the new boiler first? Or is the power flush not necessary at all?

It is likely that the guarantee for the boiler will be subject to having the old system powerflushed and a system filter fitted.

Immediately before fitting the boiler is the best time

But the sooner you fit the filter the better

This is the description of what will be performed:

Assemble and connect Proflush Thermal and Adey Magnacleanse to central heating, add
heat-reacting cleanser and heat assembly to ~70°C.
Power-flush system, one radiator at a time, alternating pump direction while operating
Vibraclean agitator to each panel radiator.
Repeat clear Magnacleanse magnets/ individual flushes until bulk of sludge removed.
Clear radiators of cleanser (individually) with cold mains through power-flush while running continuous dump-
flush out to waste pipe.
Re-install existing magnetic filter to 22mm central heating return to boiler.

Does it sound like the filter is included?

Should I find a plumber who will do both the flush and the boiler installation? This plumber no longer does boiler installation sadly.

"Re-install existing magnetic filter to 22mm central heating return to boiler."

so it sounds like you've already got one. Can you post a pic? When was it last emptied of dirt?

What is the problem you currently have, that makes a powerflush necesary?

There may be other options....

does your old boiler have a pressure gauge?

I'm not sure about the pressure gauge. There's no specific problem with the boiler but it's over 30 years old and we want to change it next year. Should we just get one plumber to do both flush and boiler installation?

if it's 30 years old, very likely it doesn't have a pressure gauge, and has a feed and expansion tank in the loft.

In this case, if you can do a bit of basic climbing into the loft, and know where your drain cock is, you could do a simple DIY chemical clean for now, and have a power flush when you get the new boiler. You can have it bundled into the installation cost.

Have you got a system filter/magnet, and can you post a pic? If so it will probably prevent any more sludge building up, but you need to periodically empty it out.

There is a boiler on the ground floor that we use to turn on the heating etc., and a huge tank (hot water cylinder) on the first floor. The loft has been converted (not by us), and has a shower, not sure if relevant. I attach a couple of screen shots and photos from the survey on the house from this summer.

Thank you so much for replying, I really appreciate it.

I can't see a system filter in your pics, see if you can identify one like it here

typically black or red plastic, sometimes brass.

I can't make out the boiler. I expect it has an opening flap near the bottom at the front where there are some controls. There might be a pressure meter in there.

As you have a modern unvented cylinder, and you say the radiators have been renewed, there might be no urgency in cleaning the system until you get a new boiler. It would be better if you can find the filter (probably next to the boiler or the cylinder) and clean it out.

Don't get a combi. Your existing white cylinder can give better hot water and will work with any wet boiler.

Thank you so much, I'll hold off on the flush then until we get a new boiler installed. You wouldn't happen to have a recommendation, would you?

And absolutely, will be keeping the cylinder. The plumber was very impressed by it and advised keeping it.

if you ask four gasmen which boiler to get, you will get five opinions, and they will all say the others are rubbish.

Vaillant, Viessmann and Worcester-Bosch are popular.

I went for a Viessmann because I like the stainless steel heat exchanger, and it is small enough to fit in a kitchen cupboard.

If you look at the manufacturers' websites you may find they have a list of local "approved installers" in your area

We've always had Vaillant in the past. I'll take a look at Viessmann too. Is it a heat only or system boiler I'd be after? (You mentioned not combi)

Either

I have regular heat only because it has less inside it.

So IMO less to go wrong and less dependent on special parts

@PigletInABlanketJohn advised me on a new boiler a year ago. I went for the Valiant with the stainless steel heat exchanger. Delighted with it and gas bills by KW are down by circa 35% compared with our old boiler. Meant I binned the British Gas useless contract I had paid for 20 years and for which you can't get them to come out now for weeks so I'm currently £700 per annum better off. Boiler will be paid for in under 4 years from savings

Do people get boiler insurance?

it is probably not worthwhile

the amount you pay per year is, on average, more than servicing and repairs woukd cost. That's how they make a profit.

Thank you so much again. And happy new year to all! 🎊