Newbie Help, Please!

[GE]

I have just (with help of plumber) had installed a 20 tube 70mm with TDC 3 going into a 230l twin coil tank otherwise heated by gas boiler. I am in Cardiff, UK. I have two things I am not sure I understand, and don't know if I have a problem or if things are fine. I have read through the manual and searched here, but can't find the answers I think I need.

Issue 1. I have had encouraging "S1" temperatures since the system was commissioned on Tuesday. Through work, Saturday (brilliant sunshine) was the first day I have been able to monitor the system in daylight. Early afternoon "S1" was showing 83C, which I though great. "S2" was at 12C and only moved to 14C by the end of the day. I went into loft to investigate, and the pipe from the manifold was (literally) too hot to touch all the way to the cylinder. The return pipe however was cold. Now it could be the heat exchange is incredibly efficient (hence I don't know if there is a problem). So the question I guess is, "should the "S2" temp rise by more than 2C when the "S1" temp seemed so much higher? If there is a problem, what is it likely to be?

Issue 2. For the last three mornings I have had a "night circulation" message. I am sure the time is properly set and (as I have anti-freeze) frost protection if off. What do I do?

Thanks in anticipation of any help!

[desperate]

Airlock would be my guess, S1 and S2 should not be more than about 10 degrees different, although that is settable in the controller. It sounds to me that you have almost no circulation.

Desp

[Antman]

GE

Is the pump actually running?
If not there is a problem in the controller settings and/or faulty pump.

Did you use a pump station? If not is the non-return valve installed backwards....

Antman

[Ted]

Check on the TDC3 menu item 2-Statistics and tell us what readings you have for operating hours and average delta T.

Also check that 4-Operating mode is set to Automatic.

Can you hear that the pump is running?

Do you have a dump radiator?

[GE]

Check on the TDC3 menu item 2-Statistics and tell us what readings you have for operating hours and average delta T.

Also check that 4-Operating mode is set to Automatic.

Can you hear that the pump is running?

Do you have a dump radiator?

Thank you all - I think there is a problem.

1. The system started operating Tuesday last and is today showing 90 hours.
2. Delta T for Saturday 67 and Sunday 35.
3, No dump radiator yet - planned however.

Today have the night circulation message, but saying "check clock". I have and its right.

Today I also have "sensor failed: 3".

More help, please!

[dhaslam]

If you check the temperature just above the pump  it will be hot if there is no circulation, in that case the pipe just below the  pump would be cold.   Check whether there is a leak anywhere, it could be hard to detect if it leaks into the insulation.

[desperate]

The night circulation may be caused by the recooling function being switched on and set below the temperature present in the manifold at night, it sounds unlikely but I can't think of any other reason for night circulation if the clock is set correctly.
The running hours and delta temperatures don't really tell us anything usefull, you need to prove the pump first by removing the bleed screw(a big chrome plated screw(if present)) on the top of the motor casing, being prepared to catch a small amount of fluid, this should let you see the end of the shaft or poke a small screwdriver onto it (gently) If it is turning further investigation is needed, if not, turn off the power and see if you can free the pump with the screwdriver and spin the shaft each way. If it feels stuck or jammed, there is probably a bit of debris (solder, lagging,etc) stuck in the impeller. If you are sure the pump is spinning, my first guess is still air, but as Antman said check that the one way valve is the correct way round, if it is then bleed the system and pulse the pump on and off repeatedly to "rock the airlock", you can manually operate the pump from the controller. If all that fails...........................................err let us know what you hear,see,feel,sense,read on the controller while doing all the above, and we think again.

Good luck mate.

Desp

[GE]

Thanks again. Plumber is back anyway on Wednesday, so I'll have another look in the morning then if out of my depth have a look with him and report back anyway.  G

[M]

GE, I'm of no help to you whatsoever, (the wife's nodding) but thought I'd give a quick hello and welcome from Rumney, Cardiff.

Hello and welcome!

Martyn (aka Mart, aka M)

[alankelly]

Hi GE

Not sure if it is any help, but on my Re-sol controller, S3 is the temperature sensor that is inserted at the top of the tank / store to monitor the top of the store for the max temperature of the store (Hot water rises so this is the part of the tank you monitor for max temperature of the store before thermal dumping) So the layout for my controller is as follows

S1 temperature sensor at collector
S2 temperature that is usually inserted in the lower part of the tank / store
S3 temperature sensor usually inserted in the top of the tank / store
S4 optional temperature return sensor for heat quantity measuring

So either S3 sensor is not present (Was controller only supplied with 2 sensors?) or S3 has become disconnected

As for the no heat transfer from collector to tank I tend to agree with the others that either the pump has stopped or more likely you have an airlock. I know on my system it was a b*gg*r to bleed and the only to fill my system was to use a drill driven pump to pressure fill the system quickly to force out all the airlocks,

Basicly all I did was have a bucket of heat transfer fluid and then pumped fluid from this bucket to one side of the pump station and then drained the other side of the pump station back into the bucket with another pipe that was imersed in the bucket fluid. And then just run the drill pump untill no air was being seen to be forced out of the exit pipe.

(Note you need to ensure that an isalotor valve is fitted betweer the fill and drain connections (in my case the flow meter) so you can close this valve to ensure fluid circulates the system forcing out all air, rather that just flowing through the flow gauge / isloator valve)

And really the only way of knowing I had flow after when in use was because I installed a pump station with a flow gauge.

Note circulaton pumps do just that, just circulate fluid and do not have enough pressure to force out stubborn airlocks to create flow.

Best regards Al.

[GE]

Thanks again.

So far as I can tell the controller was on all night (with a nightime warning again) with S1 fixed at 19C and S2 fixed at 9C.

The pipes above the pump are (not very) warm, and the pipes below cold. The return seems warmer than the supply at the manifold. The pump design appears different to that described above, so I felt out of my depth.

When I turned the pump on and off I thought I could feel a gentle whirring when on, but no sound difference at all.

Plumber back tomorrow anyway, so we'll have a look then I'll return. Thanks again in the mean time.

G

[GE]

And recooling is off.

[alankelly]

Hi GE

Just seen your post

First thing that I have noticed from your mail is that S1 is hotter than S2 (Was this reading taken at night / eary morning or mid morning ?) As from you post it seems this reading was taken either at night or when you got up

As S1 is the collector sensor and S2 is the lower tank sensor, so on these frosty nights if this reading was done at night or at daybreak then I would expect S1 to be a lot cooler than S2

I know on my system S2 at night remains at about 15 degrees (the temperature on the incoming cold water to my hot water tank) and S1 will reach 0 degres before my frost protect kicks in to heat the panel slightly.

Are you sure that the sensors are wired the correct way round??

As if they are the wrong way round this could be the cause of no heat transfer, as S1 need to be a few degres hotter than S2 (On my set up S1 need to be 7 degrees more than S2 to start pump, and pump switches of if the difference between S1 and S2 reduces to below 3 degrees)

But if they are the wrong way round and S2 is in the panel and S1 is in the tank , on a sunny day (as you had last week) S2 will always be much hotter than S1 so therefore no pump start / heat transfer (I.E  Controller thinks tank is hotter than panel!)

An easy check though, all you need to do is dip the tank sensor in a cup of hot water as see which s value changes I.E if S1 start to go up and S2 remains the same you have the sensors the wrong way round or if S2 start to go up all is as it should be.

As for you night circulation, not sure on this one but i believe the above would also cause the pump run at nigh also as it is likely that your tank will be hotter than the panel so again S1 is again hotter than S2 so pump will run until tank is same temperature as collector!

As you have stated

"So far as I can tell the controller (pump) was on all night (with a nightime warning again) with S1 fixed at 19C and S2 fixed at 9C"

And if the above is correct and S1 is hotter than S2 by 10 degrees then i believe pump will run?

Hope the above is of some help

Best and kindest regards Al
 

[GE]

143 - 8. Not the score the last time Cardiff visited the Brewery Field, but current S1 - S2 values on my controller. Plumber here and about to go up loft to investigate. Will post findings soon!

G

[GE]

Plumber had an emergency, so no update until morning. 12 - 9 at the moment.