Viessmann Vitodens 200 W System 26 KW Design Questions

[colmrenault]

Is the pump installed into vertical pipework and is it pumping up or down?

Why is the pump on 1? Have you tried the other speeds?

First time trying multi-quote, hope it works.
The pump is installed on horizontal pipework on the flow, just after the combined expansion & topping up pipe. It is on speed one because the cavitation noises on any other speed is just unbearable to listen to. I suppose it is pumping horizontally servicing upstairs but then eventually the water has to go downstairs vertically to service downstairs. I'm not sure if I've answered your question fully there.

You say that you definitely don't want to use motorized valves due to poor previous experience. What make valves did you have problems with?

My original valves were made by EPH, well that was the name on the motor anyway. The first motor stopped closing the zone when the zone thermostat asked it to so I brought that back and they gave me a replacement motor made by sauter. That lasted 6 months but then stated emmitting a constant buzzing so I returned that and thay gave me another sauter under warrenty. I was getting on fine for awhile with this then one night i looked up at the ceiling and there was a brown stain. I went up to the hot press and low and behold water was leaking out of the spindle of the motorised valve. That just finished me with them.

 

[colmrenault]

From what I can see this system zone manifold is for 2 heat sorces
Why do you need it if only working off 1 boiler your plumber could very easily make a manifold up and if you use good motorized valves instead of pumps if you ballance all the rads it would be better in long run

The beauty of the the System Zone manifold compared to one made up by a plumber is that no flow will occur in a zone if it's respective the pump is off, even if the pump beside is still on. I will try and upload the technical data sheet later.

 

[doitmyself]

The pump is installed on horizontal pipework on the flow, just after the combined expansion & topping up pipe.

If it is in horizontal pipe you need to make sure that the shaft of the pump is horizontal or very slightly higher at the vent plug end.

It is on speed one because the cavitation noises on any other speed is just unbearable to listen to.

If your tank is 3.4m above the pump, I doubt if it is cavitation.

Do you have separate feed and vent pipes, if so where do they connect to the system. If just before the pump, how far apart are they. A pic of the pipes and connections would be helpful.

I suppose it is pumping horizontally servicing upstairs but then eventually the water has to go downstairs vertically to service downstairs.

The fact that the water has to go up, down or horizontal is of no consequence. All the pump has to do is overcome the friction caused by the water travelling through the pipe. See the two references I gave.

Never heard of EPH

 

[Gray0689]

The beauty of the the System Zone manifold compared to one made up by a plumber is that no flow will occur in a zone if it's respective the pump is off, even if the pump beside is still on. I will try and upload the technical data sheet later.

Non return valves do the same thing
Myson motorised valves are good never had a big problem with them
Yes all valves can fail but never saw a myson one leak from centre

 

[Avatar]

If your friend combi didn't work i presume it wasn't plumbed in properly.

Like I said - spend the money on ripping out the old pipework and cylinder ect, and put brand new in.

How far is your kitchen/bathroom going to be from the site of the combi. If you can have the combi sited within 5 meters of both, you will have lovely hot water pressure. Although you will have to remove the old pipework first.

The type of set up you are looking at is like for an 8 bedroom house or something!

I do commercial plumbing in office buildings and the like (with multi zone valves), and what you are proposing would be rediculous for them - an office with 40 employees/8 tiolets an a huge space to heat!!!! In this office the combi is supplying 6 hot water outlets at once, that are with 5 meters of it though.

Really think it through, have some plumbers over to disguss it and wiegh up your options before you spend.

 

[Avatar]

Just to requalify, you have a 3-4 bed house with 1 kitchen and 1 bathroom right??

 

[maul]

you really need to find why you have bad circulation in your lower house circuit.
my guess is sludge restricting the flow or airlock or incorrect pipe sizing somewhere .
once you have that problem sorted all you need is 2 port zone valves (honeywell ) to control the seperate circuits.
valves do fail in time they are a moving part but they are cheap to replace.
pumps fail as well
thermostatic rad valves will also be a real godsend for efficiency as will proper balancing and pipe sizing.
simple solutions are the most reliable a multi pump system sounds a nightmare to me and its just not needed. also valves use much less power than pumps.

 

[ecowarm]

the 200w is a very efficient boiler and with the vitatronic control it will do all you ask of it without that system wiring centre thing. Bin the multi pump setup and use zone valves.
Call viessmann technical .......... very helpful and will put you right.

Also get one of their unvented cylinders to compliment the boiler.