I have a very very old boiler that works perfectly. It has recently been serviced and I also had the system cleaned with Fernox cleaner (water was clear to be frank) and 4 new small radiators fitted to the system. Then refilled with Fernox inhibitor. The boiler is only 30k BTU and the problem I am having is it is not getting the hot water or radiators as hot as I would like. I have noticed the burner is not fired up most of the time whilst the pump is on all the time. The pump only has two speed settings unlike most modern pumps which I believe have three. I am guessing the pump is not pumping the extra water, now in the system, fast enough so the water in the boiler is heating up and the thermostat is telling the burner to stop. If I fit a faster pump will this fix the problem? It is a small cottage that is not used most of the time so I would like to keep the existing, bullet proof boiler if possible. On top of that can I fit control gear to it so I can switch the heating on over the internet?
1957 I very much ddoubt it, but yea its pointing to a circulation problem and a pump might fix it, yes you could fit one of those new fangle divises to switch it on, they're not cheap though a timer will work just as well without all the rigramole
When you say the burner is not fired up most of the time, Is the flow pipe very hot and the return not nearly as hot? if thats the case its defiantly a circulation issue, if they are of similar temps it could be a thermostatic issue on the boiler. Give the guy who serviced it to have a look. Talking of pumps, if you fit a Grundfos Alfa pump it will modulate its speed to the needs of the system.
The Surveyor for the house when I bought it said in his report it was 1957. I am not sure how he knows that. Maybe there is some sort of commissioning plate or sticker. I know when the extra radiators were fitted a special pipe connector had to be used to fit metric to Imperial. The reason for the online control gear is so the house can be turned on for when we go there so it is warm. I will check the return flow pipe temperature later. I am guessing to change the thermo couple is a simple and cheap task. Looks like it is the copper wire going from the gas switch to the jacket of the boiler. Would it be best to try this myself before embarking on pump changes?
I am not absolutely sure as I have not owned it that long so with this slightly colder weather the boiler is being tested. It could have had a previous fault with the thermostat or it could be the extra radiators. Maybe a new thermostat is the way to go.
Tom the thermocouple has nothing to do with the circualtion nor temp of the water, your problem is circulation its one of two things, 1. pump could be knackered/slow 2. air lock in pipes, try this, turn the other working rads off and see if that pushes the heat to the non working rads, if it does but then goes off again when the are turned on again, its the pump, if they stay on, you had a air lock and its shifted, in 1957 NO ONE had domestic central heating, it had't been developed yet, it was the late sixties before commoners could afford central heating, central heating existed then but only as background heating in public building/churches/palaces/castles and posh folks only, so I think the survayer did a miss print unless a posh folk owned it of course
Thanks tom.plum. I thought the copper wire thing that goes into the water jacket from the gas switch may be turning the gas valve off at too low a temperature if it is faulty. Something must be controlling the gas flow versus temperature inside the jacket. Obviously there is no point in me changing this piece unless it is relevant but I thought for the few pounds they cost it might be worth a try.
Tom1965, your boiler has an adjustable temp control, yeah? That's the thermostat. I guess it could be what you suspect - the extra rads have added more water friction to your system, so the old pump is struggling to get the water flowing around there fast enough to not become too hot inside the boiler. Or, it could be the boiler thermostat is faulty so it turns off the boiler at too low a temp. Q: when you turn the temp control, can you hear the 'click'? If so, hopefully it clicks at a very low setting (or possibly not at all?) when your boiler is cold? And as the boiler heats up you should find that the 'click' occurs at higher and higher settings? So, when the boiler is turning off when you don't want it to, what setting is that control at? Pretty much 'max'? Ok, if the 'click' doesn't happen as described above - eg: it doesn't click at all or it clicks at a low temp which doesn't vary as the boiler heats up, then you may have a knacked thermostat/temp control. If, however, the click position does go higher as the boiler heats up and then you have it set to 'max' but the boiler still ultimately turns off, do you hear any sizzling or kettling from the boiler? Is the flow pipe from it very hot (ouch!) whilst the return is relatively cool (I can keep my hand on it...)? If so, that would - I think - suggest not enough flow so a better pump may be required.
Yes there is - see the temp adjuster control at the top? Well see the copper 'wire' (tube) which comes down from that panel to the water jacket? That's your baby.
It is a shooting lodge on a Surrey Estate so I guess if the Lord didn't like being cold he may have had it fitted. I will try to check all the different things mentioned and report back. I might buy a new copper pipe thingy and bolt it on seeing as they are only a few pounds. Is that called a thermo couple so I ask for the right bit? That also means if it is that I won't have a cold weekend! Thanks all for your help.
I don't think its the stat but you can check that if you like, take it out of its jacket in the boiler and blow it to cool it down, the flame should kick in, now leave it out for a minute, NOT TOO LONG or the boiler will start banking and clattering almamingly so, so afer a minute put it back in its jacket, the flame should go out, that proves the stat is working, thats a completely differant copper wire thingy than the thermacouple edit, forgot to mention, do that test when the boiler has gone out because its warm, not from start up,
(Methinks his Lordship ain't going to have a shooting lodge for too long... ) Tom, as Tom says, don't start changing things until you have a diagnosis...
So just to be sure the copper tube that goes from the bottom of the gas valve to the boiler jacket is also a thermocouple? Or is it something different? I guess if it is a thermocouple it cannot be faulty as they only send a charge when hot and that is the opposite to what is going on. I will check the outlet pipe and return pipe and also the clicking on the thermostat later and let you know what I find.
Sorry but I cannot see the relevance of that question and being that this is open forum and I have said earlier I don't go there that often I feel I cannot answere as the property could be vulnerable.
Tom'65, the tube that goes from the pilot flame at the bottom of the boiler to the gas valve is a 'thermocouple' device. This is designed to shut off the gas valve if the pilot flame goes out - it's a safety device. The copper pipe wot goes from the water jacket to the temp-adjusting control at the top of your boiler is not a 'thermocouple' but a fluid-operated thermostat control. There's a sealed 'bulb' at the end of that pipe sitting in a hole in the water jacket. Inside is fluid which expands when it's heated. This fluid acts against the temp-adjusting thermostat control to tell it how hot the water jacket is. When you turn the temp knob upwards until it goes 'click' and turns on your boiler, the bellows in that control have to move further to shut it off again - ie: the water has to be hotter to expand the fluid further and send it up to the bellows to open the electrical contacts and shut off the boiler's gas valve. If that device is faulty, it might be allowing your boiler to turn off before it's reached the desired temp. Possibly. Can you try the 'click' test I mentioned further above?
I think its a good idea for plumberboy to know your location Tom, he can set a camera in the right direction when the shooting lodge lights the sky up, both those little copper tube thingies need the cover off to play with, I live up 't north so the fall out won't affect me,
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