Hot water Cold Radiators

[matopia]

Hi All,

My wife and I recently moved into our first home and enjoyed two weeks of hot water and warm to very hot radiators.

We have an Ocean 80-FF Combi Boiler. It has a GRUNDFOS Super Selective pump UPS 15-60. Looking at the pump we have noticed there are 3 settings and at the moment the dial is set at this angle "/".

The boiler has a thermostat dial with 3 settings on it. There is also a timer on the wall next to the boiler which has 4 settings (2 for off and 2 for on). The boiler can be set to TIMER or OFF or CONSTANT.

Recently we have noticed the radiators have not been warming up, or if they do, there is no consistancy. One night they will all be 'hot as hell', but most nights we have noticed that when the boiler is set on TIMER mode, the boiler comes on, but the radiators barely warm up. Not enough to warm the house. All the radiators are the same. One night we switched over to CONSTANT and the radiators heated up properly.

We have no problem with our hot water which is running through the same boiler. I have noticed when I turn on the hot tap, the boilers flame goes from 4 burning rows to 1, then back onto 4 burning rows. The water gets hot fairly quickly. Then when the tap is turned off, the 4 burning rows change to 1 row, and about 40 seconds later the boiler returns to 4 burning rows. (There is a definite loud click from hot water use to boiler mode).

Listening with my ear to the radiator it sounds like water is passing through each radiator, so why aren't they warming up?

Since yesterday and all of today, we have not being able to get any heat out of the radiators. They are barely luke warm. Typical, as it's been freezing all day.

Some things that we have tried:

• ** Bled all the radiators bar one that had a broken valve. Only water came out of them all, and I understand that is correct.

• ** Increased the pressure between the cold entry pipe and the non return flow. - This definitely warmed up the radiators once, but never again.

• ** I was thinking there might be too much water in the system after reading an article on this forum, so drained the closest radiator with the drain pipe, thus dropping the pressure back down to 1 bar. The pressure normally sits around 2 bars.

• ** Turned the thermostat knobs on the radiators clockwise, then anti-clockwise, then to 1, 2, 3, 4, 5, and TM (whatever that is) and the radiators worked once only. Not quite sure what they need to be on.

• ** Turned the thermostat on the boiler up to 3. Can only imagine this increasing my gas bill tenfold.

So that is where we stand now. If anyone can help, or suggest something, of offer any comments, it will be much appreciated. We have looked through almost every page on this forum, and tried a lot of things that have been suggested with little success. I am willing to get a CORGI guy in if that is going to help, but would like to know roughly what the problem is, so that we are not ripped off...

Cheers,

Mike

 

[ChrisR]

SEt trv's to 5, make sure pump is on speed 3 (max), turn up boiler temp, timer on. Room thermostat?
Rads should get hot. You won't have enough rads to use all the potential output of the boiler but it should take a while to get the rads hot. All that time the burners should be on max.


What happens?

 

[matopia]

Hi ChrisR,

Thanks for your email. What is trv's? - (Do you mean the radiator thermostats?)

You mentioned turn up the pump to setting three (Did you mean the pump or the boiler thermostat?) The pump is behind the boiler cover.

The only way I know of turning up the boiler temperature is by turning the thermostat dial up towards 3. - If there is another way, then I would imagine it will be via the pump.

About the burners.... Ignoring for a minute everything that has just been said above... I will give everything a try.
I have noticed that no matter what you do to the boiler or thermostat, there are only two rows of blue burners burning. But when I turn the hot tap on in the kitchen or upstairs in the bathroom, all 10 rows of burners light up and go blue and it makes a swish noise like it's working well. Then when I turn off the taps, the boiler switches off. About 40 seconds to a minute, the boiler kicks in again, lighting up two rows of burners. (Thermostat can be on 1 / 2 / 3 it doesn't do anything more).

I am guessing this is the problem. How do I get those 8 burners burning?

Chrisz, if you can shed a little more light, that would be much appreciated.