Drained Heating system- Now rads are only warm.

[Scott.T]

PLUMBER ADVISE REQUIRED.....

drained the system down yesterday to get rid of all the sludge (after running for a week with Sludge remover in system).

Refilled system and bled all radiators and towel rail.
The system seems to be working OK and no air in rads or towel rail.

But Rads seem to be taking longer to get hot and also do not seem to get so hot to touch. They are warm/hot but not as hot as they were before.
No air as they are OK at top of Rads/Towel Rail.

Is there likely to be air trapped anywhere else ?

Are there any more air/bleed valves hidden other then the ones on the Rads ?

Would I need to rebalance the system, now that the sludge has been flushed ?

Boiler is a Potterton Profile Wall mount.

Cheers.......

 

[AND1234]

Not a plumber, but it will take longer the first time due to the room temperature water now being replaced with cold stored or mains water, so the boiler has to do more work the first time after a refill of the system. But the next time should be ok. Obviously if this is not the case with yours, forget what ive wrote and wait for the profesionals to come along...
I cant answer your other questions...

 

[Bahco]

Read post 8 in the FAQs.

 

[Scott.T]

switched system back on yesterday at 5:00pm.
It seemed to take along time to get warm and i figured this was due to lossing the stored water from the tank due to drainage.

over the evening the rad temps gradually came up, but not as hot a normal. They were hot but not so hot that you have to take your hand off after 30 seconds.

This morning, again the rads seemed to take a while to get warm before I left for work.....
the pump kicked in a few times this morning but during this first couple of pumping periods the rads were very tepid.....

(last house had newer boiler so am used to rads being hot within a few minutes)

 

[Bahco]

Did you take rads off and flush them through

Probably sludge still knocking about and a good balance will help too.

 

[Scott.T]

Did you take rads off and flush them through

Probably sludge still knocking about and a good balance will help too.

Rads upstairs are new, have replaced them in the last 6 months.
Rads downstairs have yet to be replaced (1970's style rads).

none were removed, but sludge remover was in system for 1 week prior to drainage.

Water coming out of all rads when bleeding in now pretty clear.....what drained out wasn't

I figure as there was a bit of sludge and now perhaps there isn't, that the flow is too fast....

is there anything else to bleed i.e pump or anything in boiler ? as only bled rads and towel rail.

 

[Bahco]

Read post 8 in the FAQs.

 

[Scott.T]

Read post 8 of FAQ

I assume you are refering to bleeding the pump, checking pressure valve and balancing system.

As the rest has been done or not thought to be an issue.

 

[razorrobo]

I did a similar thing this weekend fitting a new radiator, had to drain the system completly in the end as the drain valve was perished and wouldn't seal again. bleed all the radiators but rad's were still cold, heating was going for a while and pump started to get noisy so switched it off.

Needed to bleed the pump, got a gravity system feed from the loft. Pump has a metal circle in the middle/ front with a slit in it just smaller than a 10p piece, unscrew it with a screwdriver or a coin when its not running, air will come out and the tank in the loft should top itself up as it fills up the system. Should do the job

Ahh, just read again, sounds like a combi boiler so above might be void, will have to represurise/refill the boiler if not already done, normally a bypass pipe or tap on base to fill up again.

 

[Scott.T]

No not a Combi, it's a gravity feed single pump system.

Will locate the pump this evening. I guess it's in with the hot water tank...if not then it's been boxed in somehwere !!!!!!

 

[Scott.T]

Now have no DHW or Central Heating.

I guess the tank has now emptied and we are unable to gat any heat back into it.

Checking last night :
1. all rads are full of water / no air
2. pump has water in it, as dribbles out when screw removed.
3. Pump is running, as can feel it switch from i, ii and iii speed settings (it was set to iii)
4. No air vents on tank only 4 pipes, one with drain cock.

Pipe in/out of pump don't seem to be getting very hot. Ocassionally they will but a few minutes later they are tepid again.

However pump and burner seem to be running continuous.
so have switch off for now as seem to be burning gas for no reason.

 

[Scott.T]

ALL SORTED

Turned out to be Gas Supply too low.

Readers digest manul that I followed for draining suggested turning off Gas supply whilst performing Drain/Refill.

This I did, but when turning Gas back on I did not position the lever exactly where it was before......DOH!!!!!!

 

[jontheplum]

check motorized valves