Worcester + Wave = constantly running pump ??

S

slowlybutsurely

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A couple of weeks ago I had an install of a Worcester Bosch Greenstar Highflow 440CDi with the Worcester Wave controller. It might be my imagination, but I think the CH pump runs constantly. Even when it's been hours since the heating was on, I can hear and feel (near the boiler) the vibration of the pump. When I switch the boiler off (with the switch), the pump stops.

What's going on?
Best I can think of is some kind of link/jumper has been left connected that the installer should have removed?

Please - any ideas?
Thks
 
Coincidently I enquired about this today through WB's online help service. I am having a 29cdi fitted in a couple of weeks complete with a wave and I read on a forum that if the weather compensation is enabled then the pump will run all the time. Their reply was that yes this is how it works. I also asked how much power the pump consumes and they said 90W max. but that it will modulate to less than that. You can apparently set it so that it doesn't stay on in the night.
 
Just to add further info to my post for you or anyone else who finds this thread after a search. I contacted WB again today and asked if it was also possible to turn off the pump during the day by setting the desired room temperature to just frost protection. I got a far more detailed answer than expected and I have to say I am impressed with their customer service. The answer is too detailed to post here but this is part of it.
If weather compensation is turned on then lowering the target temperature would not prevent the pump from running throughout the day.
Essentially the only way to prevent the pump from running in the day time would be to turn off weather compensation.
The following explains how the weather compensation works and why it differs from a conventional room thermostat:
Weather Compensation Overview
Weather compensation is a comprehensive subject; however we will try and be as concise as possible for your reference.
When Weather Compensation (WC) is enabled the Wave no longer acts as a thermostat in the traditional sense that it will bring the boiler on until the desired room temperature is reached. Instead it becomes a controller that maintains a constant flow temperature which is dictated by a heat curve and the outside temperature. If the heat curve has been set correctly then the flow temperature should heat the room to the desired temperature. The Heat Curve is set by the parameters in the device and adjusting the parameters adjusts the flow temperature given the outside temperature.
Due to the nature of weather compensation your room temperature may be higher or lower than the desired room temperature because it is no longer a thermostat, this is to be expected. If the room temperature is drastically above or below the desired temperature then making some adjustments to the parameters should help.

Summer Disconnection
Summer disconnection will stop the central heating from coming on when the outside temperature is above the set value so that your heating system won’t operate if the outside temperature is sufficient to heat your home without an influence of the boiler.
Nightly Shutdown
Central Heating Off: This will not operate your heating at any point during your night time period unless frost protection needs to activate.
Room Temperature: This will bring on your heating should the room temperature drop below your night time temperature.
None: The heating will continue to operate under Weather Compensation during the night.
 
Wow, what a steaming pile of shoite. I bet you'll end up spending more in electricity and replacing worn-out heating pumps than you'll save on your gas bills with weather compensation. Sounds to me like someone at Woofter has cocked up the software and they're now trying to convince you that that's how is supposed to be, which it clearly isn't.

@simond I'd love to hear your thoughts on this
 
muggles said:
Wow, what a steaming pile of shoite. I bet you'll end up spending more in electricity and replacing worn-out heating pumps than you'll save on your gas bills with weather compensation. Sounds to me like someone at Woofter has cocked up the software and they're now trying to convince you that that's how is supposed to be, which it clearly isn't.

@simond I'd love to hear your thoughts on this
Click to expand...

From what I read on the other forum this system is common on the continent and America. I don't think it is an error it has to sample the radiator water temperature to know how much heat to put into the system. I'm new to all this though so I don't know how other systems operate. Bear in mind as well that a) it can be turned off if you decide its not for you and b)I'm getting a 10 year guarantee by having the wave fitted so the pump may well outlast me. I will see how well it works and turn it off if I don't think it is working well.

Edit> This thread would suggest its not only WB who use this method http://www.diynot.com/diy/threads/ufh-pump-running-continuously.298513/
 
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This is the way weather compensation generally works. Viessmann systems have worked in this way for years.

One of the factors quoted in the endless pump running justification is that at lower temperatures the heat emitters can absorb energy from warmer areas and distribute it where it is needed more.

Personally, it is my view that for most of our poorly insulated housing stock, heat zoning makes more sense and delivers greater savings than compensation.

The Worcester unit is one of the best of its type, from a usability point of view.
 
I have been able to reduce the pump running time by activating the anti-cycling function, menu 3.a and 3.b on a heatcontrol3 Greenstar 20/28 with a Wave set for weather compensation. For a light sleeper like myself, this is a relief.
But if you disconnect the Wave (painting the room) and reconnect, this setting seems to get overwritten.
The system is only 2 weeks old, I have not yet simulated the effect of a power cut.
 
Unfortunately it's not only the Germans that come up with this madness....the Dutch are equally guilty. I've had the similar issues with Atag. The only solution to stop the internal pump (circulating to the low loss header) running continuously during hot weather was to switch another resistor across the outside weather comp sensor....ie. to make the boiler think the temperature is really hot outside. The software then finally realises it's futile to run the pump.

This badly thoughtout software from the continent is one of the primary reasons the EU has forced eco pumps on the UK. Because of inappropriate German design (ie. running the pumps 24/7) the energy savings from eco pumps looked to be considerable. However, in the UK we don't generally use weather comp type systems....so there is virtually no benefit in having eco pumps. You'll be lucky to save a fiver a year on the electric bill, and given the lower reliability will probably make a loss long term.
All the pump literature from the major pump manufacturers quote exactly the same graph and supposed savings by installing an eco pump. This diagram was pulled from a German "Which" type magazine that reviewed pumps for the GERMAN heating market....ie. where they are running pumps 24/7. The graph is not relevant for the UK market and it's very dubious marketing.

As Simon mentions our housing stock is an assortment of building types. You may have a house with one end North facing, no cavity walls etc with a new extenstion the other end all fully insulated and South facing experiencing significant solar gain. Guess how your eco mad German setup will work with that.
 
I have to say that I used weather compensation during December when we were stuck in the house due to illness and it worked well as it keeps the house at a more even temperature. I would want to have more control over it now we are able to get about again. Being able to have it timed to just switch off in the night isn't enough. I also think the jury is out on whether it saves money. It probably does save money on gas but that is possibly more than offset by the cost of running the pump constantly. I keep it switched off now.
 
Gasguru said:
You may have a house with one end North facing, no cavity walls etc with a new extenstion the other end all fully insulated and South facing experiencing significant solar gain. Guess how your eco mad German setup will work with that.
Click to expand...
Do you think the Germans haven't considered this scenario?

I don't see any problem.

The weather comp curve should be set up so the coldest room in the house maintains the required temperature; TRVs take care of the other rooms. If there is significant solar gain then TRVs will shut down the relevant rads.
 
I don't thing the Germans consider anyone else.... German arrogance always dictates they do things differently. They like to over complex the design and when it fails they're happy to cheat. There's been no end of coverups from German manufacturers over the last 20 years.I won't go on but losing WW2 was in part down to ridiculous design.
 
don't be silly, dear.

That's the sort of thing the Surrey Plumbers like to say.
 
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The truth is beginning to come out...the Diesel scandal is just a long line of dishonesty about German quality engineering. Perhaps you would like to google the BMW Nikasil coverup of the 90s, BMW swirl flap fiasco, VW pumpe duse cam failures (along with poor harnesses, door switches, window lifter failures etc etc), hopeless Vaillant Ecotec models (only a dozen design faults on that model and still counting). Ever worked on white goods? Bosch/Neff oven hinges are hopeless, plenty of other examples out there.
Don't believe the perpetual nonsense about superior German engineering, they started loosing their way 20 years ago with a massive cheapening down exercise. Reunification is an expensive process and somethings got to give.
 
Not sure how or why a thread about weather compensation ended up with the diesel scandal but on the subject of Bosch appliances, in my experience they go on (almost) forever. I had a series of tumble driers that were always getting repaired then bought a bosch. I took out a five year guarantee on it which I normally never do because I thought tumble driers were all unreliable. Seven years later its still going strong. All my white goods are now Bosch apart from my fridge/freezer and they never need repairing. I'm not pro or anti Germany. I wish we could make appliances, cars etc. like them. It saddens me that we don't.
 
Having said that and getting back on subject I do regret a bit my decision to have the wave fitted. I did so because it has more features to control the boiler and to add two years to the warranty. It does work well but it replaced a hive which is an excellent device. Occasionally the wave app doesn't connect presumably because it's WiFi. The hive was rock solid as it was hard wired to the router. Also the Hive can be moved from room to room. The wave is fixed. I might actually get the hive refitted at some point.
 
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