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Andrew Smith
Andrew Smith, Plumber
Category: Home Improvement
Satisfied Customers: 3767
Experience:  City and Guilds Qualified plumber
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Cold radiators new system

Customer Question

Help... I've got a new central heating system and it was working perfectly. Just had a new bathroom fitted, including a heated towel rail. Now 2 of my radiators will not heat up at all! They are stone cold as are the pipes leading to them.
Tried all the obvious stuff, bleeding, turning the hot ones off, draining and then refilling. Still no joy.
The two that aren't working are directly above/below each other. Even my builder couldn't work out what's wrong.
Any advice/ideas please?
They aren't on a separate circuit
Submitted: 2 years ago.
Category: Home Improvement
Expert:  Andrew Smith replied 2 years ago.
It sounds like they are airlocked.What happens if you turn the pump up and turn all the other radiators off?
Customer: replied 2 years ago.
I've tried turning all the other rads off and just leaving the 2 "broken" ones on. Not sure what you mean by pump? My builder put a pipe on one to drain it while leaving the tap on to refill the system... Is that what you mean?
Expert:  Andrew Smith replied 2 years ago.
Is the circulating pump in the boiler or in the airing cupboard?
Do you have a cylinder?
Customer: replied 2 years ago.
It's an Elnur electric combi boiler. I have no tanks.
Expert:  Andrew Smith replied 2 years ago.
You need to check the pump speed and turn it up if you can.The pump is in the boiler
Expert:  Andrew Smith replied 2 years ago.
Customer: replied 2 years ago.
Ok, I've taken the front off the boiler and locatedthe pump. It has a slot on the control that needs to be turned with a screwdriver.
How do I do this though? Is it best to have the boiler turned off, or heating on etc. How much should I turn it? Can it be on too high and cause damage?
Expert:  Andrew Smith replied 2 years ago.
You can adjust the speed with the power on.
Turn it up one and then try turning all the rads off again except the faulty one and see if it will force through
Customer: replied 2 years ago.
There are two controls on the pump, the turny slot thingy and a black lever.
Not sure how to attach a picture. There aren't any numbers on the dial. How much do I turn it? Can I do any damage if I get it wrong? The manual seems to talk about water coming out?
Expert:  Andrew Smith replied 2 years ago.
Water will only come out of the centre screw.You are looking for a slot near the electrical connection
Customer: replied 2 years ago.
Ok, so if you look at the diagram in figure 5.3... Which bit should I be turning? Or below the stuff shown in the diagram is a black knob with "3 bar" on it... Is that what you mean?
Expert:  Andrew Smith replied 2 years ago.
The bit with 3 bar on is the PRV, dont touch that.5.3 shows it on the left hand side of the pump on the cover
Customer: replied 2 years ago.
Ok, that's the black lever. It was in the fully down position. It will only allow me to more it up a very small a,punt before cutting out and showing fault E3
Expert:  Andrew Smith replied 2 years ago.
That is insufficient flow rate, you will need to turn it back up again
Customer: replied 2 years ago.
So in the down position it is already set at the hardest flow? So that isn't the issue?
Expert:  Andrew Smith replied 2 years ago.
No does not look a likely cause.It appears like we have done all we can via this medium, you will need to call an engineer to cure this.