also noticed a water trickling sound, in the pipes above the boiler, during about the first 30mins.
ideal classic RS250 kettling
- Thread starter cypher007
- Start date
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shouldn't be, but who knows. I thought the pump should have pushed the air out, unlike when it was reverse flowed and the air kept being pushed into the heat exchanger where it got stuck until the pump turned off, at which point it would just sit in the pipe work until the pump turned on again.
do you think from the readings that the pump is ok?
do you think from the readings that the pump is ok?
Yes, but at those temperatures was the boiler not already short cycling which was your initial complaint?
Certainly being slightly less than 11 C the pump seems fine on setting "3" but should only normally be used on "2".
What are the readings on setting "2" and while still heating up?
Tony
Certainly being slightly less than 11 C the pump seems fine on setting "3" but should only normally be used on "2".
What are the readings on setting "2" and while still heating up?
Tony
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the original problem is that the boiler is kettling.
ok had some time to run the system up tonight.
pump setting 2:
0min 22 flow pump running boiler off diff 0
1min boiler on 1min later boiler making low hissing sound
5min 34 diff 9
7min kettling
10min 38 diff 9-10
15min 43 diff 10
20min 46 diff 10
25min 50 diff 11
30min 53 diff 12
35min 57 diff 13
40min 62 diff 14
45min 67 diff 16
50min 71 diff 17-18
last reading just before timer turned off, the boiler stat was about to trip also, roughly 90secs after the 50min reading 73 flow diff 19.
so it seems the higher the flow temp goes the bigger the differential.
pump setting 2:
0min 22 flow pump running boiler off diff 0
1min boiler on 1min later boiler making low hissing sound
5min 34 diff 9
7min kettling
10min 38 diff 9-10
15min 43 diff 10
20min 46 diff 10
25min 50 diff 11
30min 53 diff 12
35min 57 diff 13
40min 62 diff 14
45min 67 diff 16
50min 71 diff 17-18
last reading just before timer turned off, the boiler stat was about to trip also, roughly 90secs after the 50min reading 73 flow diff 19.
so it seems the higher the flow temp goes the bigger the differential.
is the differential ok at nearly 20c?
No it should be about 11 C.
Perhaps TRVs were closing and you dont have an auto bypass valve.
Its odd that it was about correct at a lower temp.
When doing these measurements the boiler and room stats should be turned to max to stop the boiler cycling.
Its very difficult giving advice when we dont see all the installation all in one easy to assimilate place.
We could walk around your house in two minutes and know everything.
Tony
Perhaps TRVs were closing and you dont have an auto bypass valve.
Its odd that it was about correct at a lower temp.
When doing these measurements the boiler and room stats should be turned to max to stop the boiler cycling.
Its very difficult giving advice when we dont see all the installation all in one easy to assimilate place.
We could walk around your house in two minutes and know everything.
Tony
the rad in the hall has both valves wide open. I think theres a bypass just after the pump that was fitted with the unvented. the boiler stat was on max.
I put some x400 in, as a last throw of the dice, and it seems to be working. the boiler is definitely quieter. but it seems the flow temp is lower, I need to check but on the face of it it would appear to have improved the flow to the point where the boiler cant keep up with the heat being taken out.
incidentally I think the boiler is probably undersized, as its a 14kw. how would I go about sizing a new one?
incidentally I think the boiler is probably undersized, as its a 14kw. how would I go about sizing a new one?
after x400 for about 5 days:
0min 23 diff 6-7
5min 28 diff 8
10min 31 diff 8
15min 35 diff 8
20min 38 diff 8
25min 41 diff 8
30min 44 diff 9
35min 47 diff 9
40min 50 diff 9-10
52min 58 diff 11
then about 30mins later with boiler cycling on its stat:
65 diff 10
so it appears to have made the differential more stable, but at the cost of a very long heat up.
0min 23 diff 6-7
5min 28 diff 8
10min 31 diff 8
15min 35 diff 8
20min 38 diff 8
25min 41 diff 8
30min 44 diff 9
35min 47 diff 9
40min 50 diff 9-10
52min 58 diff 11
then about 30mins later with boiler cycling on its stat:
65 diff 10
so it appears to have made the differential more stable, but at the cost of a very long heat up.
some on here may remember the problem of the kettling rs250.
well today I did some gas consumption tests. this has flagged up a possible cause for the slow heatup, kettling, and crazy temps on the bottom of the heat exchanger but no where else.
ive checked the manual and as follows:
min gas consumption 14.9 kwh
mid 16.7 kwh
max 18.3 kwh
well mine, according to a 10 year old gas meter, is using 12.95kwh.
seems a tad low. what apart from incorrect setup could cause this? is it worth getting a GS to tune it up and see if it behaves?
well today I did some gas consumption tests. this has flagged up a possible cause for the slow heatup, kettling, and crazy temps on the bottom of the heat exchanger but no where else.
ive checked the manual and as follows:
min gas consumption 14.9 kwh
mid 16.7 kwh
max 18.3 kwh
well mine, according to a 10 year old gas meter, is using 12.95kwh.
seems a tad low. what apart from incorrect setup could cause this? is it worth getting a GS to tune it up and see if it behaves?
forgot to mention since using the x400, and leaving it in the system permanently the kettling seems to have all but gone, just has a wheezing sound now bit like a kettle just starting up.
I expect that you have never had it serviced !
Getting it properly serviced and the power setting increased to about the middle of the range would be a good idea!
Reading all the previous posts, I notice that you did not mention pump setting when posting the diff temps. Diff and pump speed at inter related.
Tony
Getting it properly serviced and the power setting increased to about the middle of the range would be a good idea!
Reading all the previous posts, I notice that you did not mention pump setting when posting the diff temps. Diff and pump speed at inter related.
Tony
your guess is as good as mine. we moved in nearly a year ago, and didn't find much evidence of servicing. when I had the cover off I found no end of crap laid in it.
how much should a service cost? would they take the covers off the heat exchanger and check its not full of crap also?
oh the wheezing noise seem to be coming from the magnaclean pro 2 I fitted. so im guessing its just the water cavitating.
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