Worcester Bosch Highflow 440 - reliable?

Buzzark · 28 Jul 2007

One of these looks techincally ideal for our purposes including the siting as we currently have a floorstander and a space in just it's right size.

Wall mounted boilers seem to be a slight issue in that we seem to have downpipes or soil pipes or other things stopping the natural places in the kitchen that one would fit meaning we'd have to be pulling apart the kitchen to fit one elsewhere..

Anyway, technically it fits the bill and I know the brand is normally reliable, but oddly I've found loads of bad reviews about the 400 series in terms or reliability.
While I suspect that a number of them might refer to the earlier 400 pre condensing model, it is obviously of some concern. It's not that normal to find bad reviews of single models, e.g. try looking for bad reviews of a 35 CDi - practically non-existant!

Does anybody have practical experience with these to reassure me and put it back on the shortlist?

Gasguru · 28 Jul 2007

There have been many versions of this boiler. Many gas installers have had bad experiences when servicing/repairing them. I for one always refer owners back to Worcester for there fixed price repair since I can do without the hassle as they can be very labour intensive when it comes to repairs.

I don't find Worcesters (with the exception of the older models eg 230's, 24i RSF range) any more reliable than other makes. The older CDI's are renowned for being horrrible to work on. The new condensing range are not much better.

Remember that many boiler models are still too new to have an idea of their long term reliabilty (some Worcester installers are able to offer extended warranties).

Worcester are expensive boilers since they spend more than any other manufacturer on advertising. I(t would be better if the advertising buget went on better design.

gas4you · 28 Jul 2007

I personally don't rate Worcesters at all. I service a few Highflows and they are ok to service but I won't repair any Worcester and as previously said I always refer customer to Worcester for repair.

Highflows are ok when storage tank is full but when depleted you are back to a very low power 23Kw combi

Have a look at the Vaillant ecotec Plus 937.

Buzzark · 28 Jul 2007

gas4you said:
Have a look at the Vaillant ecotec Plus 937.

I've got that one on my shortlist.
It contains 15l of secondary water right? Does it use that bit by bit to suppliment, or all in the beginning?
My notes say 0.75 bar to give the full quoted 15l/m which makes it pretty efficient in theory on a less powerful supply.

The WB isn't faring to well so far...

Agile · 29 Jul 2007

There is a slight siscrepancy between any combi boiler and your apparent desire to have a 25 li/min shower.

Even a 500 li unvented cylinder will be emptied by your wasteful shower in 20 minutes!

The 937 does not seem to stand up to technical scrutiny on its performance. The natural flow rate of about 15 li/min is augmented by stored heat for what I calculate to be only about six minutes.

I am waiting for Dave who has fitted some to tell us just how long it can actually deliver its rated output of 20 li/min @ 35°C temperature rise.

Part of its secret is that the store is heated up to about 75°C so the 15 li will heat at least twice that volume of DHW.

Tony

Buzzark · 29 Jul 2007

Agile said:
There is a slight siscrepancy between any combi boiler and your apparent desire to have a 25 li/min shower.

Even a 500 li unvented cylinder will be emptied by your wasteful shower in 20 minutes!
Tony

I'm only really after 16+ as 16 is what we get currently of the pumped system and I'm pretty happy with that. 18 would be a good result and a shower with more just means the ability get get that clean feeling quicker so I'd be out in 5 minutes probably.

I can't see how the Valliant could deliver sustained performance, the WB uses a 60L heatbank so that's easy to see how that would work as long as miracles aren't expected.

JB Gas · 29 Jul 2007

Installed a 440 2 weeks ago amazing performance good to fit considering size first one I have fitted. I recommend a 42cdi but the difference in flow rate is noticable true two tap operation as long as you have the mains

staffs · 29 Jul 2007

I know a few lads who have installed the vaillant 937 and they can only give it total admiration and have said the hot water flow rate is superb and easily manages to cope with two bathrooms.

Remember though it is quite a big and heavy piece of kit so any wall fixings must be capable of the weight of the unit when full. Also you will need to fing a suitable area to locate it as the depth of the unit is quite deep.. 600mm ?

Dan Robinson · 29 Jul 2007

The Multi p1sses all over the Vaillant and Highflow in everything but size. AND its only 24kW.

The Highflows were OK if you wanted to lose your washing machine space

. The older ones that we deal with had a problem with sludge collecting in the return filter - not a hard job in itself but if the unit was fitted tight into cupboards then access was a pain. Although I suspose practice makes perfect. I don't know if this problem extends to the newer models. Thankfully we only have half a dozen to worry about.

esra_ptrap · 29 Jul 2007

I've been fitting 440's since they came out.

They are an excellent boiler, good to fit and service with excellent performance and as reliable as any of the other top end boilers.

Sure, if you want to run 2 baths one after the other, the first will fill in a couple of minutes but the second will take a few minutes longer ... Ho Hum.

I have one fitted in my 4 bedroom home with 3 bathrooms all with baths and powerful showers (excellent water pressure where I live) and never have any problems with enough hot water. Of course we have to be sensible ... My wife wouldn't run a bath (for example) if I was having a shower as the flow would drop off but these kind of considerations in the real world don't cause any inconvenience and negate the need for a far more complex (and space hungry) storage solution.

After all, people generally fit combi's for simplicity and the 440 is a great compromise of performance v simplicity of installation/space.

It looks great in the utility room also

Buzzark · 29 Jul 2007

esra_ptrap said:
Of course we have to be sensible ... My wife wouldn't run a bath (for example) if I was having a shower as the flow would drop off but these kind of considerations in the real world don't cause any inconvenience and negate the need for a far more complex (and space hungry) storage solution.

Usage wise we've got 1 bathroom with it's own shower and I'm only considering either a single bath or shower performance. Mornings consist of * SHOWER - 5-10 mins - SHOWER *. Despite my "demands" I'm actually quite realistic in how I want the solution to perform.
Are the 440's essentially a completely different boiler from the 400's?

@ Dan_Robinson
The Atmos multi would be great but I've discussed it with my better half

and there's pretty much no way to fit it in the current kitchen design without destroying half the place. There are natural places for floor standers to go, but each one thwarts the idea by sticking existing pipes/walls/windows in exactly the wrong places.

Our current floor stander fits under the cabinet but has a window at about 1100mm from the floor so that's about our height limit. She wasn't too receptive about having something stick up in front of it.

Another slight issue is that I've not yet been able to find a recommended plumber with a G3 ticket so that does throw up a further complication.

Dan Robinson · 29 Jul 2007

Then I would agree that the Highflow is your next best option. Along withh te Vaillant - which probably won't fit under the worktop...

simond · 29 Jul 2007

We have fitted around 10 of the new Highflow 440s and have yet to experience an installation or in service defect. Which is more than we can say for the rest of the current WB range.

We have now fitted a number of the new Vaillant 937s and whilst an excellent product based on the old aquaPLUS - we have had three instances of customers complaining of water hammer. Which is, I think, more than a coincidence.....

The first one (fitted in the week of the 937 launch) was visited by Vaillant service and they recommended putting a PRV on the mains, which was odd because the standing pressure was 3.5bar max.

This did not make any difference (as expected!) so we put a shock arrestor in line on the incoming line and this stopped the noise. Still waiting for their feedback on the other two.

gas4you · 29 Jul 2007

Agile said:
The 937 does not seem to stand up to technical scrutiny on its performance. The natural flow rate of about 15 li/min is augmented by stored heat for what I calculate to be only about six minutes.

I am waiting for Dave who has fitted some to tell us just how long it can actually deliver its rated output of 20 li/min @ 35°C temperature rise.

Part of its secret is that the store is heated up to about 75°C so the 15 li will heat at least twice that volume of DHW.

Tony

Tony, the 937 is rated to give 200 litres of 'blended hot water' @ 35C rise in 10 mins to be precise, then if actostor is used up will still give 15+ litres /min @ 65C.

The actostor recharges in 2 minutes.

It has a seperate storage loading pump that is fully modulating depending on flow of the hot demand and presumably set by the aquasensor that detects the flow via a paddle and hall effect sensor.

The 15 litre store is actually 2 x 7.5 litre tanks and from wha I can ascertain these are charged and depleted individually depending upon demand and flow rate. Being 15 litres it does not fall under the G3 regs either.

As already mentioned the drawback is its size and weight, but is still a lot smaller than a highflow and performance wise runs rings around it.

Of course as usual to get the full advantage of its benefits needs a proper site inspection and fitting and commissioning as to MI's, without this individual site performances will vary

Agile · 29 Jul 2007

The 400 was a pretty unreliable boiler unless the system was totally clean. Thats the installers fault not the boilers. They were difficult to work on and many engineers avoided them.

The 440 seem to have designed out the blockage points or perhaps they are just being fitted now by people who clean the system properly.

I would still recommend an unvented cylinder and a nice cheap boiler to suit like a Worcester 15Ri or 18Ri depending on property size. The extra cost of the cylinder is considerable reduced by the much cheaper boiler.

The other advantage of the cylinder is that it can be heated by electricity should the boiler fail or as seems incresingly likely a political upheaval causes a shortage of gas supplies.

Tony

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Worcester Bosch Highflow 440 - reliable?

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