Desperate for help with Central Heating Problem!!!!! (Part II)

[foodluva]

Since the cold snap we feel our house is just not being heated and if it weren't for our gas fire in the living room we would be really struggling. Our Corgi engineer called out a Ravenheat engineer who travelled from England (we live in Glasgow) to look at our boiler. He opened it up and after a while declared there was nothing wrong with it and reckons we have a circulation problem. (he said the pipes running into the 2 radiators in question were really hot suggesting that something was obstructing entry of this hot water to the radiator). He did however change the thermistor as a precaution. Since then nothing has changed. Interestingly, the downstairs radiators that are giving us the problem (living room and kitchen) were not replaced when the others were so we are about to purchase 2 new ones in case there is debris in them which the powerflush has not removed. However, when we both came home last night there was an obvious heat when we came in the front door and we found both radiators to be really hot. This did not last more than an hour.

My question is, do you think I have a circulation problem or a faulty boiler? How can I check for a circulation problem before I go on the phone to Ravenheat all guns blazing?

A million thank you's for any advice please!!

[TWR]

Hi, I don't know if this will help, with the heating on to full, close (ALL ) radiators depending on the amount of rooms you have, pick out what you think is the last radiator from the pump, take withyou a Flat bowl to catch the water open the bleed niple not too much & try. then do that with every other radiator you have. Good Luck.

[foodluva]

Thanks for the advice TWR. The Ravenheat engineer suggested this but warned that this may dislodge debris which could potentially work its way elsewhere in the system which could be a disaster if it gets into my boiler. I will see the installer about the air problem. Ravenheat suggested air as well. It strikes me as strange that my fitter hasn't suggested this.

[TWR]

Again, We had a fresh rad put into the living room for a while it was OK then started acting the goat, the System has been in our house for 16 yrs no probs until this last one what I done is what I have stated, after that no probs. I am not a heating Engineer but common tells you if its banging Its air, I repair to a point my own home what with prices the way they are, going back to what I said in your other post, If you have already paid for this system to be put in then that's the problem & cost to the people that put it in.

[foodluva]

hanks again TWR. Much appreciated.

[foodluva]

TWR if I do what you suggest re closure of radiators am I just trying to bleed them individually of air whilst the others are closed or am I removing water? If wate rcomes out the bleed valve should I stop? (Sorry I'm a woman!!!!!)

[TWR]

Hi, the only thing you are doing although the Nipple will be open is getting rid of the air, when you open the said item just open it a couple of turns, do not be tempted to take it out ( they are a sod to get back in ) after the "HISSING" has stopped close the said thing and go to the next radiator & do again then so on until the last rad, put a towel on the floor under the bowl to catch the water that runs down the rad itself, I feel after this you will be pleased with yourself.

[TWR]

Dont knock yourself, as said you will not be doing anything to damage you system, yes there will be a spray of water coming out of the Bleeder (Nipple) but do not worry about that, that;s the Norm, Yes, what you are doing is bleeding all the rads one at a time.

[foodluva]

Thanks very much - it's all clear now. I'll give it a go! Thanks for your very prompt replies.

[gucciman]

do you have thermostatic radiator valves (trv's) fitted to the 2 radiators that aren't heating up properly?

i think you are barking up the wrong tree thinking the problem is down to air has the air in a system always rises upstairs.
i also dont think the boiler is at fault becase the rest of your rads are presumably working ok

presuming that you do have trv's fitted then unscrew the head off the trv's of the rads that are faulty and then see if the rads get hot. if they do get hot without the trv head on then the head is at fault and should be replaced. if removing the head doesn't make a difference then it could be the body of the trv at fault.

the other thing worth trying is turn off all the upstairs rads and see if that forces the heat downstairs into the 2 faulty rads (hot water always rises upstairs so you need to force it downstairs, this is called balancing the system) if that works then you need to get a heating engineer in to balance the system properly.

as i see it you have a 2 options if the 2 suggested fixes above don't work


you could get the 2 faulty rads replaced along with the valves.

you could call british gas in and ask them to investigate the fault. (get a price first)

[gucciman]

apologies, i have just seen your other post.

is the boiler a combi boiler or a conventional one where you have a hot water cylinder and header tanks?

i think you have 2 problems.

the rads getting hotter upstars than downstairs is a classic sign that the system needed balancing.

the fact that the downstairs rads are better now the systems been balanced apart from 2 of the rads suggests that those 2 rads are at fault or the valves.

if the downstairs rads as a whole are still not warm enough then there could be a circulation problem, see what speed the pump is set to, turn it up to max if its not already, you could try having a more powerful pump fitted.

i would also be looking to see if the burner pressure on the boiler is correct although the ravenheat engineer should have done that.

[foodluva]

Thanks Gucciman. It's a combi boiler I've got. I do have TRVs on my radiators so I will try what you suggest as well as what TWR suggested. The Ravenheat engineer checked the pump speed and pressures and all were good. He also suggested that the boiler noises were caused by air. I am loathed to go down the more powerful pump route as the fitter says that my boiler is powerful enough to add another 6 radiators. I'm really hoping that one of these suggestions solves my problem but I'll update this thread to advise of any progress. Still think it's weird that the radiators were roasting the other night though for a short time.

[terambulan]

Without reading other replies - CH systems go on and off according to temp of water to be heated. Maybe increasing the water temp would help.

[gucciman]

the boiler noises could be made by air but a combi powered sealed system is very easy to vent of air unlike a conventional tank-fed system. firstly the boiler has an auto-air vent fitted that should remove most of it (providing the air vents cap is looseand not screwed shut) then you can vent the pump by loosening the large screw in the middle to let any air out (then re-tighten the screw) some boilers also have manual air-vents on the main and secondary heat exchangers, although not many do, and lastly you vent the upstairs rads (with the boiler off so you don't suck air in)

when the engineer says that the boiler is powerful enough to run another 6 rads he is referring to the burner pressure and power output of the boiler rather than the pump. as a quick check see if the pump fitted in the boiler is what it says it should be in the boilers instruction book and check that it is actually set to max speed which is usually 3.

the fact that your happy with the other rads still suggests to me that this is not a boiler problem but a localised problem with the 2 rads and the valves

[foodluva]

Well it's getting worse. Today my hot water went cold an I had to switch the boiler off and on again to get i working. Also the 3 rads which don't heat up as good hve gone from roasting hot to warm. And the encore? This evening my hot water became not very hot. I switched the boiler off in the hope that I could resolve things by turning it back on. It now won't turn on at all! Am calling out Ravenheat in the morning. I am told the chances of them replacing my boiler are next to nil however, I have had problems since the day it was fitted so feel they should.