Q for all u plumbing hotshots out there.

buky

hello everybody,

I have an old system. Recently, I put a stat on my circulation pump on oil boiler. When i turn on the heat the pump will not kick in until the water reaches the set temp. I have gradually decreased the stat setting over the past few weeks as having problems with it.

Firstly, as the water is hot when the pump kiks in, there is then a rush of hot water which causes loud ticking noises on all the rads. I dont mind this but as there are rads in their rooms near the beds, it wakes the kids up in the morning or at night. Before there was not this noise as there was no pump stat an the water gradually increased in heat while flowing around the rads in turn gradually heating them.

2nd prob is that lately I have a lot of air in my system. I have a non return vavve near the oil boiler and its here the air gets locked. I release it an 3 weeks later its there again. Never had the prob before installing stat so Im gussing it has to do with that rush of hot water somewhere.

My q is, can I wire the system to kick on the pump when the heating is turned on, but when I turn off the heating the stat kicks in and leaves the pump running until the water cools down to the set temp ?

tks

aujopimur

Keep it simple, get rid of the pipe stat and let the pump run with the boiler.

M cebee

yes you can prob use it for overrun
if the system is suited for it

but you need a permanent live feed

stat goes on flow if I recall

Billy Bunting

Why did you feel you needed a pump overrun ?? sounds like you have the stat up very high, what is it set at ??

buky

tks lads for replies,

bunting an aujo... I was told it makes for a longer life for the boiler if the very hot water is pumped around and not left always in the boiler. and I have seen also that after I switch off the heat the rads stay hot for a long time due to the pump over-run. Much longer that before. So in essence, I am getting more heat for my money.

at the moment i have the stat down to 30 degrees.

m ceebee.....I have a permanent live feed but its not that simple.
Follow this..the heat is switched on. Live going to burner an on to pump.
All working together. Then the heat is switched off. Live feed to burner and pump cut. I have my permanent live feed to the stat, which controls the pump. But the temp is high so the stat is open an still allows power to the pump, whicch is what I want. But the pump is also wired to the burner so , in effect, keeps the burner going and the heat on! Can anyone see this?

So, lads, tks for replies, but none have answered the question. Do you know?

My q is, how can I wire the system to kick on the pump when the heating is turned on, but when I turn off the heating the stat kicks in and leaves the pump running until the water cools down to the set temp ?

Billy Bunting

buky wrote: »

tks lads for replies,

bunting an aujo... I was told it makes for a longer life for the boiler if the very hot water is pumped around and not left always in the boiler. and I have seen also that after I switch off the heat the rads stay hot for a long time due to the pump over-run. Much longer that before. So in essence, I am getting more heat for my money.

at the moment i have the stat down to 30 degrees.

Not an easy one without seeing the set up....

You need the pump overrun kicking in at around 60o, below that you'll get condensation and products of combustion causing corrosion, the stat will need to be on the flow as close as possible to the boiler or it will overheat, depending on the boiler we're talking about ?? It does sound like your getting pump cavitation because the temp is to high.

buky

bill, I understand what you are saying but you still have not answered what I asked. nothing personal, but you are skirting the q and the issue. I want electrical specifics how to achieve what I asked. No more theories or projections.
If I dont get an answer to the q asked, thats fine. But there is no point replying if you dont know the answer.

Cheers

Billy Bunting

buky wrote: »

bill, I understand what you are saying but you still have not answered what I asked. nothing personal, but you are skirting the q and the issue. I want electrical specifics how to achieve what I asked. No more theories or projections.
If I dont get an answer to the q asked, thats fine. But there is no point replying if you dont know the answer.

Cheers

Well BUK!!

My point was!! are you operating it correctly? it's quite obvious you have no clue what your doing and quite honestly with your attitude i suggest you go back to the guy who first suggested it and ask him you Q.

Welcome to Boards.

heinbloed

@ buky:

As aujomopir said: keep the pump running with the boiler and forget about the thermostat controlling the pump. Someone gave you bad advise on this issue.

This is how oil and gas boilers in CH system are usually operated, the pump is always on.
Modern boilers will have a pump integrated which will sense temperature and pressure changes and reduce or increase the volume pumped around, their speed.
But they are never switching-off. Unless the boiler is switched off.

buky

thanks Heinbloed,

cheers for that.

now now bill ole boy...temper temper! no need to get all hot an bothered just cos you couldnt answer the question.

buky

buky wrote: »

I want electrical specifics how to achieve what I asked. No more theories or projections.

you may me able to do it with a relay, but its only a theory which is no good to you.

M cebee

a stat with a changeover contact
perm feed and a switched live
-as long as theres somewhere to pump water

should a basic oil boiler have pump overrun?

aujopimur

I want electrical specifics how to achieve what I asked. No more theories or projections. .

Cheers[/QUOTE]
If you want to use some of the residual heat in the boiler you will need a permenent live to the boiler, a pump overrun stat, and a relay.
You can buy a set of controls for a modern boiler to make things easier.

anuprising

what you want is extremely basic - I normally do it thru a wiring center if zones going in but what you want should take about 10 mins

at the moment your pump cuts in when boiler reaches say 35 but cuts out when boiler cuts out ? you want over run until water cools down ?

take pump off the boiler circuit , and supply it with its own permanent feed live neutral and earth . the pipe stat you have at the moment cuts in at 35 , if you wire it the opposite way it will cut out at say 30 or 35 - break the neutral thru the stat . if your pipe stat is wired common , 1 and 2 , leave common where it is and change wire from 1 to 2 or vice versa

heres what will happen , boiler will fire up when it hits 30 ( or whatever you set it at ) pump will kick in and circulate heated water
when temperature is satisfied the boiler will knock off , but the pump will continue to run as the water temp is high (60 or more )
the pump will only cut out when the water cools to the preset temp on the pipe stat (30 or lower?) pump is independant of boiler now on its own electrical feed , effectively a pump over run

is this what you wanted ?

buky

Thanks lads,

I have the information I need.

Cheers