Central Heating Leading to Divorce!!!!

[portugal99]

Thanks for everyones replies so far...

In answer to questions

1) What was asked for was a system that would heat the house! With the capability of adding in solar heating/hot water. The solar side is a 'nice to have' as we do not plan to install the solar until next year. But we obviously need to have the heating working this winter!

2) What was promised was heating throughout the whole house, radiators and floor heating. In one room it was sugested that radiators would NOT be required because the floor heating would be more than enough to heat the room. Even with TWO radiators in the room neither floor nor radiators have reached any significantly noticeable temperature and ti remains very cold!

3) The pipework shown in the photo is pretty much all of it. The only two pipes that are not shown are on the accumulator one is said to be an outlet for heating the lower one a return. There are other pipes on the very top of the accumulator but I believe that they are for the solar system when installed.

4) Sorry I dont understand what pe x is? Is it good practice?

5) Yes that really is the inlet from the range that high up. You can follow the pipe from the tank back to the blue box which controls the water from the range. My understanding is that the inlet is that high up to create good stratification within the accumulator.

It's all very frustrating. the engineers left yesterday after modifying the system to take water directly from the accumulator to the floor but the pump only runs when water is delivered from the range and not all the time to at least TRY and pump hot water around the floor!

Since the modifications yesterday the system is WORSE as neither radiators nor floor are working at all.

In my mind the 600l of water should be delivered to the floorand/or radiators ALL the time or at least until a desired temperature is reached. Obviously if the water delivered into the deposit is insufficient to maintain the temperature in the accumulator then we are a bit closer to finding a solution but this way, without the abillity to deliver ALL hot water into the accumulator AND to run the pumps to push the hot water around BOTH systems then we are really not going forward in any way.

Look forward to hearing more useful comments and suggestions please!

 

[Onetap]

Hi Tony

Unfortunately not however, the actual water boiler holds 70l of water and when the range is running it does heat and deposit that water in anywhere between 30 seconds and 1 minute depending on wood and settings on the range.

Post a picture of the range, please.

Is this a direct range, i.e. a thing like an Aga, but with the facility to draw off the 70 litres of water in the boiler and use it for cooking & washing?

The heat is going somewhere. It's either inadequate heat input (which is what I'd suspect) or inadequate insulation and the UFH heat is being lost into the ground. The range may be inefficient with a lot of heat going up the chimney. Is the 24 kW rating the total heat output or heat output to the water?

What make & model is the 3-way valve?
I think I would have piped it differently.

Q = 70/30 x 4.2 x 60 = 588 kW or so, depending on what the dT is; (70-10 gave me the 60 degC).

 

[Onetap]

Cannot seem to be able to upload onto the site but here is a link to one of the photos.

Any air vents on high points? How do they get the air out, and the water into, the pipes?

Isolating valve on the flow from a woodburner? Yee-har.

 

[portugal99]

The range is pretty srandard. Firebox for burning wood and then a 'backboiler' which holds approx 70l. On the back of the range is a thermostat that is set to, lets say, 75°. Once temperature of the water is reached then the pumps run and take the water from the range. Similar to all other ranges I have looked at including Aga just with more water capacity. With relation to water capacity, there appears to be 2 schools of thought....

1) Less water so that it heats faster and is delivered faster to the radiators/accumulator
2) More water as the accumulator/heating system is so big that it needs that amount of water.

Confused dot com or what!!!

The total rating of the range is 25kw I would suggest. the range was hand built by a local company who have been making these for years without problem BUT only for direct heating i.e. pumping water from the backboiler straight to radiators.

3 way valve? the blue box? It appears to be an MUT? Italian I think.

Again, for me, if the hot water is being delivered directly to the accumulator and this is reaching nearly 70° then does that not suggest that the range is working well?

The UFH is well insulated with foam inlay below and a special concrete additive assist with heat (i think).

 

[portugal99]

There are air vents on top of the accumulator (I think). The water in? Not sure I understand that one sorry?

I am not liking the "Yee-har"!!!! I assume that is relating to the 'blue box'?

 

[htgeng]

There are air vents on top of the accumulator (I think). The water in? Not sure I understand that one sorry?

I am not liking the "Yee-har"!!!! I assume that is relating to the 'blue box'?

no, the yee-har is relating to the iso valves. There shouldn't be any. In the same way you don't use that type of pipe on a stove which could hit high temps. Do you have the installation instructions for the stove? There should be a hydraulic diagram for the plumbing. Take a picture of it and upload. Where is the header tank for the heating system.

I really think you should be looking at getting another specialist company to provide a report. Sorry to hear you spent 13000 E on that and not got a working system.

 

[Onetap]

There are air vents on top of the accumulator (I think). The water in? Not sure I understand that one sorry?

One thing that catches my eye is the pump on the extreme left. The pipes are in flow & return pairs (although not necessarily next to one another) to each device. The pipe adjacent to the LH pump is flow to radiators, so the pump is I assume (dangerous assumption) return from radiators, pumping upwards. OK so far.

The pipe from this pump goes up, along and down; there should be an air vent on that pipe or it will air lock. I don't see one, but that doesn't mean there isn't one. A missing air vent could stop the whole show.

Since that pipe goes down next to the flow from the wood burner, is this pipe the return to the wood burner? If so, it suggests the pump is isolated from the woodburner by the MUT valve when flow is directed to the store. Is there another pump adjacent to the woodburner?

There is another up-along-down pipe in front of that with no obvious air vent.

I thing you need to follow the pipes and sketch out a schematic of the system if you want anyone to be able to work out what's wrong with it.

 

[portugal99]

Your assumptions are correct.

The pipe from the blue box is the feed to the radiators. The pump then 'lifts' the return, up along and down. There is no air vent on this or any other pipe that has the same characteristic.

Yes the pipe is the return to the wood burner. There is no pump adjacent to the wood burner... but this pump still runs when the MUT valve is diverted to the store.

I hope this latest image with flow directions helps a little...

http://www.freeimagehosting.net/uploads/67e06f6a3e.jpg

 

[portugal99]

After a very long meeting with the installers they have decided to come back tomorrow and try a few other things... especially as this is the FIRST TIME they have installed such a system!!!!

Things that are going to be tried tomorrow....

1) Bypass the accumulator. the installers are sugesting that the power rating of the range is only 7 - 8kw!!! I cannot believe this, especially as the manufacturer has quoted 25kw AND has the same range running a heating system with 90 elements. I am not convinced that this is going to prove too much in all honesty.

2) Try to find a way of running JUST the floor heating from the accumulator.

Option 2) is, in my opinion, the best temporary solution until a certified engineer is available to check through the whole installation.

The problem with option 2) is that the pump for the floor heating will ONLY run when water is delivered from the range. There is currently 40° of water sitting in the store and it just isnt getting used anywhere.

I want a manual switch to turn the floor heating pump on and see if we can maintain 40° in the store with ALL hot water deposited from the range into the store. Apparently it is not possible to have a "manual" switch.

Is there any reason NOT to have a manual switch on this pump?

 

[Norcon]

Can you ascertain that the accumulator is up to temperature and then check the flow temperature from the UFH mixing valve when the pump is running? Ideally with an instrument and not just placing your hand on it.
Should be around 30-40c.
(There may be a temperature guage at the manifold and if so check that)
What make of mixing valve is it?
And then check the flow rate through the loops at the UFH manifold if flow meters are fitted.

Just looking at the image I would be doing some re-arranging to the pipe work.

Breifly.....
1- Have the wood burner feed direct the accumulator.
2- One outlet feed to both UFH and radiators with a primary circulator supplying the tmv and rads.
3- Fit a laddomat thermo regulatory valve.

I don't understand what that pump to the left of the image is doing connected to a loop of pipe going into and out of the surface.

 

[portugal99]

The accumulator achieves somewhere between 60° and 70° when the range is firing on near full power. This is indicated by a thermostat on the accumulator.

The mixing valve is Duco, German I think.

I have no idea what the flow rate is as there are no flow meters!

 

[Norcon]

OK so your accumulator is heaing up.
Can you check the flow temp on the outlet of the tmv whilst the ufh circulator is running?
(ensure the accumulator is up to temperature!)
Also check the flow temperature into the valve from the accumulator.


Remove the insulation and place your hand on it and make a guess if you have too.

 

[portugal99]

Not sure what the tmv is sorry but the water is leaving the accumulator as I can feel the outlet manifold(?) getting warm... Where the 4 different floor circuits are connected.

There is a cut off thermostat on the 'manifold' set at 45° to cut the pump if this temperature is reached. I have succeeded in achieving this and then regulated the hot water using the Duco valve.

 

[Norcon]

The tmv is the duco valve.

If you are getting 45c at the manifold and it has already shut down the ufh pump on overheat then your ufh should be working providing the accumulator temp is maintained.

Ideally you should measure the temperature on the outlet of the duco (tmv) valve.
As said it should be between 30-40c and maintained for at least two hours.

 

[portugal99]

Hi Norcon

Superb, maybe now getting somewhere!!

The issue is this... Yes I can get 45° at the manifold, quite easily actually. The problem is that the pump will only run when there is a delivery of 70° water to the deposit.

Now, as the accumulator is only delivering 40 - 45° of water to the ufh the bursts that the pump is running are very short and I do not believe long enough to complete the 1km of ufh tubing. There is then a cooling period before the next short bust of the pump.

I had a thought.... would it be possible to put a thermostat on the RETURN of the ufh so that IF that reaches 5°, for example, the pump would shut off.

Maybe I am looking at this the wrong way but there must be a way of running the pump whilst there is sufficient hot water in the accumulator!?!?